College readiness among high school students can be measured by the actual performance of college students and their correlated scores on ACT tests for English, mathematics, reading, and science. As part of its Course Placement Service, ACT has compiled an extensive database of course grade and test score data from over 90,000 first-year students across 98 institutions. These data provide an overall measure of what it takes to be successful in selected first-year college courses. The data were weighted so that they would be nationally representative of two- and four-year postsecondary institutions nationwide. The college readiness benchmark scores are the minimum ACT subject-area scores associated with a 50 percent chance of earning at least a B or a 75 percent chance of earning at least a C in corresponding college classes (ACT 2010). In academic year 2009–10, about 47 percent of high school graduates took the ACT, and of ACT test-takers, some 66 percent met the college readiness benchmark score for English, which predicts performance in college-level English composition (ACT 2010). Some 43 percent of test-takers in the same year met the benchmark for mathematics (a predictor for college-level algebra), an increase from 39 percent in 1996–97. About 52 percent of the ACT test-taking population in 2009–10 met the benchmark for reading (a predictor of performance in college-level social sciences)—a decrease from 54 percent in 1996–97—and about 29 percent met the benchmark for science (a predictor for college-level biology). No significant upward or downward trends were found for English or science between 1996–97 and 2009–10.