Well done! I'd say you've made something incomprehensible to the general public more approachable - but as someone with stats in my background (not epidemiology) I think I'm not your target audience.

That said, if there were an actually-causal effect, I'd expect to see it in differentials between states - just in the number of days per year the windows had to be closed - and I note that Florida shows a lower rate than Illinois or New York - but there's a fairly long windows-closed season in Florida.

All that said, there are some gas ovens that produce some carbon monoxide (figures as it's potentially-constrained combustion). As I remember it was mostly the cheaper models made pre-2000 (nat gas and propane). Simplest thing is to get a CO alarm - which we all should have anyway.