Of the 1,480,469 people who took the ACT in their Sophomore, Junior, or Senior years and who graduated in the last year (Class of 2009), 638 of them earned the perfect composite score of 36. This represents about 1 in 2,320 (99.96th percentile) students, up from last year's 1 in 3,300 (99.97th percentile). Scores of 33, 34, 35, and 36 all were in the 99th percentile. The average score was 21.1. This is unchanged from 2008's graduates. The state with the highest average score was Massachusetts, at 23.9. The lowest scoring state was Mississippi, at 18.9.
In Spring 2008, all public high school eleventh graders in the states of Colorado, Illinois, Kentucky, Michigan, and Wyoming were tested with the ACT as required by each state. Colorado, Illinois, Kentucky, Michigan, and Wyoming students who met ACT's 2009 graduating class criteria are included in the 2009 graduating class average score results. Consistent with ACT's reporting policies, graduating class test results are reported only for students tested under standard time conditions.
The ACT also released several interactive graphs to demonstrate increases in students tested, average scores, etc.
All of this information can be found here: ACT National and State Scores for 2009
This is the official press release: ACT Press Release : 2009 ACT College Readiness Report News Release