Table:
text: List of cities in North America
Most populous cities
Most populous cities
Rank_ City Population Year_of_Census_or_Estimate Country
1 Mexico City 8851080 2010 Mexico
2 New York City 8175133 2010 USA
3 Los Angeles 3792621 2010 USA
4 Toronto 2791140 2011 Canada
5 Chicago 2695598 2010 USA
6 Houston 2099451 2010 USA
7 Montreal 1854442 2010 Canada
8 Ecatepec 1655015 2010 Mexico
9 Guadalajara 1564514 2010 Mexico
10 Philadelphia 1556396 2010 USA

Question: In list of cities in North America, in which census year or estimate is the population of Toronto greater than 1,556,396?