From what I've heard and read, the numbers released by the province were debunked and rejected by pretty much everybody. Having visited a few times, I don't see how the number could possibly be so low.
Its because they don't record the all too typical situation of a Canadian Citizen with financing via foreign relatives/friends.
Eg. Chinese family has one member whose been granted citizenship. They all come together to pool money, transfer it to the Canadian relative, purchase together, profit(for now).
All thats recorded is a Canadian purchased a home, "how" they purchased is not yet a government issue.
The government/banks/real estate industry has known about this for years...