The average composite score on the ACT dropped slightly this year, to 21.1 from 21.2 on a 36-point scale. While the composite score on the ACT has been edging upward slightly in recent years, officials said that the slight decline was to be expected in a year in which the ACT saw significant increases in the total number of test takers, since such spikes typically add to the pool many students who have not taken college preparatory courses.

For the high school class of 2008, 1.42 million students took the ACT, a 9 percent increase from the previous year and a 21 percent increase from 2004. Between 2006 and 2008, the percentage of high school graduates taking the ACT increased to 43 percent from 40 percent.

Traditionally, the Iowa-based ACT has been strongest in the Midwest while the SAT (for which annual scores will be released later this month) was dominant elsewhere. But increasing numbers of students in what have been SAT strongholds have been taking the ACT -- although in many cases they take both tests, since virtually all colleges will accept either one, and then submit the better score. Many college counselors say that students who do well in high school courses but who don't "test well" tend to do better on the ACT than on the SAT.

Among the states with significant increases in the percentage of high school graduates taking the ACT over the last two years, where the ACT was once uncommon: California (14 to 17 percent), Connecticut (12 to 19 percent), Maryland (12 to 16 percent), Massachusetts (13 to 17 percent), New Jersey (8 to 13 percent), New York (17 to 23 percent), Oregon (13 to 30 percent), and Pennsylvania (9 to 13 percent). Michigan hit 100 percent this year as the state moved to use the ACT as part of its assessment system for high school students, so those gains are less the result of students' decisions than those elsewhere.

The ACT has four parts. The mathematics score was unchanged this year at 21.0. English and reading each saw drops of one-tenth of a point, English to 20.6 and reading to 21.4. Science dropped two-tenths of a point, to 20.8.

ACT officials noted that, as in past years, there is a direct correlation between completing college preparatory high school courses and test scores. This year, the percentages of students who met what the ACT defined as benchmarks for course preparation were unchanged from last year: 43 percent for math, 53 percent for reading, and 28 percent for science.

Over the last five years, the ACT population has become more diverse. The percentage of ACT test takers who are white is now 63 percent, down from 67 percent. At the same time, score gaps among racial and ethnic groups have grown, with the black average dropping, white and Latino averages up slightly, and Asian American showing major gains. Last year, the Asian average composite of 22.6 was 1.4 points greater than the average for all students. This year's Asian average of 22.9 was 1.8 points greater than the average for all students.

The following table shows this year's totals, by racial and ethnic group, with changes over 1 and 5 years.

ACT Composite Scores by Racial and Ethnic Group, High School Class of 2008