Projections of Education Statistics to 2021

NCES 2013-008
January 2013


Table A.  Mean absolute percentage errors (MAPEs) of enrollment projections, by lead time, control of school, and grade in elementary and secondary schools: 2012
Statistic Lead time (years)
1 2 3 4 5 6 7 8 9 10
Public elementary and secondary schools                    
Prekindergarten–12 enrollment 0.3 0.6 0.8 1.1 1.3 1.4 1.6 1.9 2.3 2.6
Prekindergarten–8 enrollment 0.3 0.6 1.0 1.3 1.4 1.6 1.9 2.4 2.8 3.3
9–12 enrollment 0.4 0.7 0.9 1.1 1.2 1.5 1.8 2.2 2.4 2.5
Private elementary and secondary schools                    
Prekindergarten–12 enrollment 3.4 4.6 3.7 7.2 7.7 10.6 9.3 9.4 8.1 6.3
Prekindergarten–8 enrollment 3.5 4.9 4.1 8.0 9.2 12.1 10.6 10.4 10.2 7.9
9–12 enrollment 3.0 3.8 2.3 4.3 2.8 5.8 5.7 6.1 1.3 1.3
NOTE: Mean absolute percentage error is the average value over past projections of the absolute values of errors expressed in percentage terms. MAPEs for public PK–12 enrollments were calculated using the last 28 editions of Projections of Education Statistics. MAPEs for private PK-12 enrollments were calculated from the past 10 editions. Calculations were made using unrounded numbers. Some data have been revised from previously published figures.
SOURCE: U.S. Department of Education, National Center for Education Statistics, Projections of Education Statistics, various issues. (This table was prepared February 2012.)