It's be hard to track the number who stay and for how long. Just because they're coming to Canada doesn't mean they stay long term.
Many immigrate, explore, then move on. Others hope that Canada is a softer immigration path into the US. This seems to have some Merritt in the past, though I'm not sure how effective that strategy is now.
I have heard this elsewhere, that Canada loses a lot of its immigrants either to return or another destination (most likely the US).
The rate of immigration is not as high as the headline number for this reason, but 20% of Canada's population is still foreign born which exceeds the historical peak in the US during the 1900s and 1910s.
Anyways, here's one source https://www.statista.com/statistics/443063/number-of-immigra...