I have lived in both the US and Canada long term and I've found the Upright/Canister split to be the same. But I will say from my very unscientific findings, just general "living there" knowledge I'd say there is more central vacuums than the US. But definitely not the majority.
But from what I understand from older vacuum fans, America's 'appreciation' of Henry is about similar to the UK in the '80s, just before they got into large retailers like Argos.