I think the stats are province-wide, but they would be heavily biased by the numbers in the GTA, Brampton-Peel, Ottawa, and Windsor-Essex regions. So I suspect that the % would be close between all those.
And as the absolute number of cases goes up, the proportion of that 20% who get bad Covid goes up as well (including requiring ICU care and fatalities).
I think there’s two things behind that: the ones who just don’t care, believe they are immune, or think the worst they face is ‘a bad cold’; and the ones stuck in service/sales jobs dealing with the public on a daily basis because they need to eat.
I haven’t seen the GTA breakdown in a while, but the worst areas are of course the lower end of the socioeconomic scale - lots of dense 1960s rental apartment buildings etc.