Statistics Canada conducts a country-wide census that collects demographic data every five years on the first and sixth year of each decade. The 2016 Canadian Census enumerated a total population of 35,151,728, an increase of around 5.0 percent over the 2011 figure. Between 2011 and May 2016, Canada's population grew by 1.7 million people, with immigrants accounting for two-thirds of the increase. Between 1990 and 2008, the population increased by 5.6 million, equivalent to 20.4 percent overall growth. The main drivers of population growth are immigration and, to a lesser extent, natural growth.