The U.S. Department of Education's National Center for Education Statistics has released long term trend figures charting the progress of students in three age groups from the early 1970's until the end of the 1990's. Generally, the trends in mathematics and science are characterized by declines in the 1970's, followed by increases during the 1980's and early 1990's, and mostly stable performance since then.
Some gains are also evident in reading, but they are modest.
Overall improvement across the assessment years is most evident in mathematics. Average scores from 1984 to 1992 were higher than in 1971. The slight increase between 1971 and 1999, however, was not statistically significant. Average scores increased during the 1970's. Average scores increased during the 1970's.