DES MOINES, Iowa (AP) – Iowa is ranked No. 2 among states where more than half of graduating high school students took the ACT college entrance exam. A report issued  Wednesday says 61 percent of Iowa’s 2011 high school graduates took the ACT, compared with 72 percent in Minnesota, the state with the highest ACT score. Iowa’s average composite score was 22.3 out of a possible 36. Minnesota’s average was 22.9. The national average was 21.1.  The ACT report says 31 percent of Iowa students who took the test reached benchmark scores that suggested they are ready for college. That’s up a percentage point from 2010. Nationally, 25 percent of this year’s graduates tested as college-ready.