That Emporis data is incorrect,
SkyscraperPage.com has a full listing of every building with 10 or more floors under construction in the city of Toronto, it consists of 133 buildings. It numbers 306 if you include proposed buildings.
Toronto - SkyscraperPage.com
There are currently 25 buildings with 10 or more floors under construction in NYC. If you include
proposed buildings, NYC's number only reaches 80.
New York City - SkyscraperPage.com
NYC is actually more like 3 times Toronto's population - in any case, Toronto is blowing it away right now.