Average score or cut score is higher than the 2015 average score or cut score at the .05 level of statistical significance.

Average score or cut score is lower than the 2015 average score or cut score at the .05 level of statistical significance.

NOTE: U.S. trend tables show data for all available years. Standard error is abbreviated as s.e. The United States met guidelines for sample participation only after replacement schools were included in 2003, 2007, and 2015. The United States' National Defined Population covered 90 to 95 percent of the National Target Population in 2007, 2011, and 2015.

SOURCE: International Association for the Evaluation of Educational Achievement (IEA), Trends in International Mathematics and Science Study (TIMSS), 1995, 2003, 2007, 2011, and 2015.