As of the 2006 Census, there were 100,646 inhabitants in St. John's itself, 151,322 in the urban area and 181,113 in the St. John's Census Metropolitan Area (CMA). Thus, St. John's is Newfoundland and Labrador's largest city and Canada's 20th largest CMA. Apart from St. John's, the CMA includes 12 other communities: the city of Mount Pearl and the towns of Conception Bay South, Paradise, Portugal Cove-St. Philip's, Torbay, Logy Bay-Middle Cove-Outer Cove, Pouch Cove, Flatrock, Bay Bulls, Witless Bay, Petty Harbour-Maddox Cove and Bauline. The population of the CMA was 192,326 as of 1 July 2010.

In what year where there 100,646 inhabitants in St. John's?