Average scores on the ACT college entrance exam dipped slightly for the high school class of 2008 as the number of students taking the exam jumped by 9 percent compared to last year.

This year's results, released Wednesday, reveal that more than three in four test-takers will likely need remedial help in at least one subject to succeed in college. But the ACT's creators said it was good news that average scores held nearly steady even as more students took the exam. That means the total number who've earned benchmark scores showing they're ready for college-level work is rising.

"In terms of the number of students who are ready this year compared to last, we are talking about genuine progress," said Cyndie Schmeiser, president and COO of the ACT Education Division. "More students are reaching at least a minimum level of readiness for college-credit courses. We're keeping a lot of kids from having to take remedial level courses. That translates to millions of dollars that are being saved at the state level."

The average ACT composite score was 21.1 for the class of 2008, compared to 21.2 a year ago, on a scale of 1 to 36.

"We have a more heterogeneous population of test-takers, so we're including those kids who weren't considering college or aren't considering college," Schmeiser said, explaining the slight decline.

A record 1.42 million — or 43 percent — of this year's high school graduates took the ACT. It was the first time a full grade level of students had been required to take the exam in Michigan, which joined Illinois in Colorado as the only states mandating the ACT statewide. Kentucky and Wyoming began administering the test statewide this year for the class of 2009, and a growing number of school districts are requiring all students to take the ACT.

Some of the growth is also coming from states like New Jersey and Connecticut, where students have historically taken the SAT exam, but are increasingly taking both tests to try to boost their college application credentials.

That raises questions about whether some high-achieving students are propping up average scores nationally, painting too rosy a picture of how most students are really doing. But ACT officials said they do not think that's the case. They said about two-thirds of this year's growth came from states where the ACT is the more popular test.

In those states, the "new" test-takers would tend to be relatively low scorers who might not have been considering college previously, so on balance the growing pool is likely depressing test scores, not inflating them, officials said.

ACT scores continue to show huge gaps remain between the preparation students receive in high school and what they need to succeed in college. Only 22 percent met a benchmark score for college readiness in all four subjects — English, math, reading and science. That's a one-percentage-point decline from last year.

On three of the subject tests, the proportions earning scores that indicate college readiness were identical to a year ago — math (43 percent), reading (53 percent) and science (28 percent). The proportion showing college readiness in English fell one point to 68 percent.

Most colleges accept scores from either the ACT or SAT exams, though they test different material. The ACT is more curriculum-based, while the SAT focuses more on basic skills. SAT results for the class of 2008 are due later this month.

The ACT, an Iowa City, Iowa-based nonprofit, says a major part of the shortfall in college readiness is that students are failing to complete a core curriculum of college-prep courses. Students who take a recommended core sequence — four years of English, and three each of math, science and social studies — are significantly more likely to meet benchmarks.

But ACT also maintains the core courses need more rigor. Among 2008 graduates who took the minimum core curriculum in math — algebra I and II plus geometry — just 14 percent met the math benchmark.