Statistics Canada says the national population almost hit 37 million last year as it grew at the fastest rate among G7 nations.

The agency says Canada's population was just over 36.9 million on census day last year, growing by 5.2 per cent between 2016 and 2021.

The five-year growth rate was double that of any peer country in the G7, and Statistics Canada says most of the growth happened prior to the onset of the pandemic in 2020.

Statistics Canada says the main reason for the slowdown in growth was border restrictions that, while meant to slow the spread of COVID-19, also slowed the pace of newcomers arriving in Canada.

The agency says population growth was at a record high before the pandemic, and then slowed to its lowest rate in a century in 2020.

Statistics Canada says there were about 1.8 million more people calling the country home in 2021 compared with 2016, with four in every five being immigrants.

Immigration has been key to driving population growth as the birthrate has declined, but the agency notes that rate in 2021 hit its lowest level of record.

Statistics Canada says some of that slowdown might be pandemic-induced. The agency points to one of its studies done late last year that suggested adults under 50 wanted to have fewer children than previously planned.