there are a couple of important caveats.
the poll distinguishes inter alia active, non-active, drop out, etc.
“informed” is another important distinction, but not made. here’s what i mean.
poll after poll shows up to 90% percent of catholics misunderstand high profile doctrine, esp. like IC, “infallibility,” etc.
so who’s fault is that? is it lack of education or what? imo, the church has to take a fair amount of blame. anytime you assign a name to a doctrine and then immediately have to add–but it doesn’t mean what it sounds like–then you’ve lost the battle. so, transubstantiation: yes, it uses distinctively aristotelean vocab but it doesn’t rely on aristotelean phil–hey, that’s a problem, and one that the eastern churches who believe the same thing don’t have.
same goes for “birth control.” how many catholics truly know what church teaching is, know what Natural Family Planning is, what the different methods of NFP are? Not very many in my experience. Again the church has much to answer for, although it varies by diocese. due to intransigence, however, the church as a whole has not been evangelizing NFP as a positive good until recently–having practically lost the public debate by default.