Iowa ? Average scores on the ACT college entrance exam have inched downward this year, yet slightly more students who took the test proved to be prepared for college, a report out today says.

Last spring’s high-school seniors averaged a composite score of 21.0 on the test’s scale of 1 to 36, down slightly from 21.1 last year. It was the lowest score of the last five years.

At the same time, 24 percent of ACT-tested students met or surpassed all four of the test’s benchmarks measuring their preparedness for college English, reading, math and science. That is up from 23 percent last year and 21 percent in 2006.