Indeed they are towards the bottom, but not "tied for last".
Talking about statistics, take a look at the "Estimated % of Grads Tested" column. the top 20 do not break 20%, while the bottom is near 100% with the exception of Hawa'ii.
As for % tested, states that don’t mandate the ACT tend to have higher performance in general. They don’t have as compelling of a need for the mandate, and they have many students who’d rather just take the SAT on its own. There is an effect going the other way though - if you don’t mandate the ACT, then students who don’t want to take any standardised testing at all…won’t, and so they won’t depress the average score.