____________________________________________________________________________________________________________________________________________________________
 Percentile |   1971    |   1975    |   1980    |   1984    |   1988    |   1990    |   1992    |   1994    |   1996    |             1999
            |           |           |           |           |           |           |           |           |           |___________________________________
            |           |           |           |           |           |           |           |           |           |Total      | Male      |Female
____________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________
     1      |    2      |    3      |    4      |    5      |    6      |    7      |    8      |    9      |    10     |   11      |   12      |   13
____________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________
            |                                     9-year-olds
            |_______________________________________________________________________________________________________________________________________________
Average ....|207.6 (1.0)|210.0 (0.7)|215.0 (1.0)|210.9 (0.7)|211.8 (1.1)|209.2 (1.2)|210.5 (0.9)|211.0 (1.2)|212.5 (1.0)|211.7 (1.3)|208.5 (1.6)|214.8 (1.5)
Standard    |           |           |           |           |           |           |           |           |           |           |           |
  deviation | 42.1 (0.4)| 38.6 (0.3)| 37.9 (0.4)| 41.1 (0.4)| 41.2 (1.0)| 44.7 (0.8)| 40.3 (0.6)| 40.5 (0.8)| 39.0 (0.8)| 39.1 (0.7)| 40.6 (0.9)| 37.5 (0.9)
            |___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________
Percentiles |           |           |           |           |           |           |           |           |           |           |           |
  5th ......|134.8 (2.0)|143.2 (1.3)|148.5 (1.6)|140.5 (1.2)|141.9 (3.6)|134.8 (3.2)|140.7 (1.6)|140.1 (2.6)|144.6 (2.4)|143.4 (1.3)|138.8 (1.6)|149.7 (3.1)
  10th .....|151.6 (1.6)|159.2 (1.1)|165.1 (1.4)|156.7 (1.2)|156.7 (2.1)|150.1 (1.9)|156.0 (1.5)|155.6 (2.5)|159.7 (2.1)|158.3 (1.4)|152.9 (2.3)|164.2 (2.6)
  25th .....|180.0 (1.3)|185.2 (0.8)|191.1 (1.2)|183.7 (1.2)|184.3 (1.8)|178.7 (1.8)|183.1 (1.5)|184.1 (1.9)|186.1 (1.3)|185.0 (2.0)|180.3 (1.8)|189.3 (1.6)
  50th .....|209.3 (1.0)|211.9 (0.8)|217.2 (0.9)|212.6 (1.0)|213.7 (1.4)|210.3 (1.5)|213.6 (0.9)|214.8 (1.1)|215.4 (1.2)|214.8 (1.7)|211.5 (2.3)|218.0 (2.7)
  75th .....|236.7 (1.0)|236.5 (0.9)|241.3 (1.0)|239.6 (0.9)|240.1 (1.3)|240.3 (1.8)|239.3 (1.2)|240.0 (1.5)|240.3 (1.0)|239.4 (1.4)|237.1 (2.1)|241.4 (1.6)
  90th .....|260.5 (0.8)|258.1 (0.8)|261.7 (1.1)|262.8 (0.9)|263.0 (1.7)|265.7 (1.8)|259.9 (1.2)|260.1 (1.6)|259.7 (1.0)|259.3 (1.1)|258.4 (3.0)|259.9 (2.7)
  95th .....|274.1 (0.9)|270.6 (0.1)|273.3 (1.6)|276.5 (1.4)|277.5 (2.0)|280.4 (1.3)|272.1 (1.2)|271.7 (1.5)|271.8 (1.3)|272.3 (2.3)|271.8 (3.4)|272.6 (2.0)
            |___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|______
            |                                    13-year-olds
            |___________________________________________________________________________________________________________________________________ ___________
Average ....|255.2 (0.9)|255.9 (0.8)|258.5 (0.9)|257.1 (0.6)|257.5 (1.0)|256.8 (0.8)|259.8 (1.2)|257.9 (0.9)|257.9 (1.0)|259.4 (1.0)|253.5 (1.3)|265.2 (1.2)
Standard    |           |           |           |           |           |           |           |           |           |           |           |
  deviation | 35.7 (0.4)| 35.8 (0.3)| 34.9 (0.4)| 35.5 (0.3)| 34.7 (0.5)| 36.0 (0.6)| 39.4 (0.8)| 39.8 (0.7)| 39.1 (0.9)| 38.4 (0.8)| 38.9 (1.1)| 37.0 (1.0)
            |___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________
Percentiles |           |           |           |           |           |           |           |           |           |           |           |
  5th ......|192.8 (1.8)|193.5 (1.1)|199.1 (1.9)|196.7 (1.1)|199.5 (1.7)|195.7 (1.9)|190.9 (2.8)|188.2 (4.9)|189.1 (2.3)|193.4 (2.6)|186.3 (3.6)|203.0 (3.0)
  10th .....|207.8 (1.4)|208.7 (1.0)|212.8 (1.5)|210.2 (0.9)|212.9 (1.2)|209.8 (1.8)|207.9 (1.9)|205.1 (1.7)|206.4 (2.1)|209.2 (1.6)|201.4 (1.9)|217.5 (2.4)
  25th .....|232.3 (1.2)|232.9 (1.0)|235.3 (1.1)|233.9 (0.8)|234.2 (1.2)|233.2 (1.0)|234.7 (1.8)|232.5 (1.2)|233.1 (1.5)|234.2 (1.1)|227.4 (2.0)|240.4 (1.2)
  50th .....|257.0 (1.0)|257.7 (0.9)|259.6 (0.8)|258.2 (0.8)|257.9 (1.1)|257.3 (0.9)|261.6 (1.6)|260.1 (1.1)|260.1 (0.9)|261.0 (1.5)|255.2 (1.4)|266.3 (1.5)
  75th .....|279.9 (0.8)|280.6 (0.8)|282.8 (0.8)|281.6 (0.6)|281.4 (1.4)|281.5 (0.8)|287.0 (1.4)|285.2 (1.1)|284.8 (0.8)|285.8 (1.6)|281.1 (2.4)|290.7 (2.6)
  90th .....|299.6 (0.9)|300.5 (1.0)|302.3 (0.8)|301.7 (0.8)|301.6 (1.0)|302.0 (1.0)|309.2 (1.8)|307.4 (1.4)|306.1 (1.4)|308.2 (2.4)|302.3 (2.3)|312.3 (2.1)
  95th .....|310.8 (0.9)|311.8 (1.0)|313.9 (0.8)|313.7 (1.0)|313.7 (1.3)|314.4 (1.3)|321.9 (2.6)|320.3 (1.4)|319.3 (1.8)|320.1 (1.2)|313.7 (1.7)|324.9 (2.0)
            |___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________
            |                                    17-year-olds
            |___________________________________________________________________________________________________________________________________ ___________
Average ....|285.2 (1.2)|285.6 (0.8)|285.5 (1.2)|288.8 (0.8)|290.1 (1.0)|290.2 (1.1)|289.7 (1.1)|288.1 (1.3)|287.6 (1.1)|287.8 (1.3)|281.5 (1.6)|294.6 (1.4)
Standard    |           |           |           |           |           |           |           |           |           |           |           |
  deviation | 45.8 (0.5)| 44.0 (0.6)| 41.8 (0.6)| 40.3 (0.3)| 37.1 (0.7)| 41.3 (0.7)| 43.0 (0.6)| 44.4 (1.0)| 42.2 (0.8)| 41.8 (0.8)| 42.8 (1.2)| 39.6 (0.8)
            |___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________
Percentiles |           |           |           |           |           |           |           |           |           |           |           |
  5th ......|206.1 (1.5)|209.3 (3.0)|213.0 (1.7)|219.9 (1.3)|226.1 (1.3)|220.0 (2.3)|214.3 (2.9)|210.8 (3.6)|214.1 (2.5)|215.0 (4.5)|206.8 (3.2)|228.7 (5.7)
  10th .....|225.3 (1.7)|228.4 (1.7)|230.6 (1.8)|236.0 (0.9)|241.5 (2.2)|236.9 (3.1)|232.7 (2.7)|230.0 (3.1)|232.0 (1.7)|233.1 (3.7)|224.5 (2.3)|244.4 (1.9)
  25th .....|255.9 (1.6)|257.8 (1.1)|258.7 (1.2)|262.5 (1.1)|265.7 (1.8)|263.5 (1.3)|262.6 (1.1)|259.8 (1.8)|259.9 (1.1)|260.7 (2.2)|253.0 (2.2)|268.4 (1.6)
  50th .....|287.7 (1.4)|287.9 (0.7)|287.5 (1.4)|290.3 (0.9)|291.1 (1.9)|291.1 (1.3)|293.0 (1.2)|289.9 (1.8)|288.9 (1.9)|289.2 (1.8)|283.2 (1.6)|295.3 (1.6)
  75th .....|316.7 (1.0)|315.7 (0.7)|314.6 (1.2)|316.8 (0.9)|316.0 (1.4)|318.6 (1.5)|319.4 (1.4)|318.7 (1.8)|316.4 (1.6)|316.4 (1.2)|311.2 (1.9)|321.6 (1.9)
  90th .....|341.7 (1.1)|340.0 (0.9)|337.5 (1.4)|339.6 (0.7)|336.9 (2.1)|342.7 (2.1)|342.7 (1.8)|343.0 (1.8)|341.0 (1.7)|340.6 (2.2)|335.3 (2.6)|345.4 (2.9)
  95th .....|356.5 (1.5)|354.3 (0.7)|350.9 (1.3)|352.6 (1.0)|348.7 (1.8)|356.0 (1.7)|355.8 (1.9)|357.7 (1.7)|355.1 (2.6)|355.1 (1.7)|350.3 (6.4)|359.1 (3.0)
____________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________|___________

NOTE: All age groups exclude persons not enrolled in school. These test scores are from the National Assessment of Educational Progress (NAEP). The NAEP scores have been evaluated at certain performance levels. A score of 300 implies an ability to find, understand, summarize, and explain relatively complicated literary and informational material. A score of 250 implies an ability to search for specific information, interrelate ideas, and make generalizations about literature, science, and social studies materials. A score of 200 implies an ability to understand, combine ideas, and make inferences based on short uncomplicated passages about specific or sequentially related information. A score of 150 implies an ability to follow brief written directions and carry out simple, discrete reading tasks. Scale ranges from 0 to 500. Some data revised from previously published figures. Standard errors appear in parentheses. SOURCE: U.S. Department of Education, National Center for Education Statistics, National Assessment of Educational Progress, NAEP Trends in Academic Progress, various years, by Educational Testing Service. (This table was prepared August 2000.)