There are now more than 35 million people living in Canada, Statistics Canada reported Thursday.

The agency reports that on July 1, 2013, Canada's population was estimated at 35,158,300. That's an increase of about 404,000 people over the last 12 months. The population grew 1.2 per cent over the last year -- an increase similar to the average annual gains over the last 30 years.

International migration was responsible for two-thirds of the growth in the last year, Statistics Canada says. In fact, since 1993-1994, net international migration has been the main source of population growth for Canada.

Three-quarters of Canadians are now living in three provinces: Ontario (38.5 per cent), Quebec (23.2 per cent) and British Columbia (13.0 per cent).

Over the last year, the population rose highest in the western provinces, thanks to record levels of both international migration as well as from people moving from other provinces.

Population growth was conversely lower in the Atlantic provinces in the past year. In fact, Nova Scotia's population actually declined by 0.5 per cent. The only other region that saw a population growth decline was Northwest Territories.

In the Atlantic provinces, low population growth in the last year was driven by residents leaving the province for other provinces, as well as low "natural" population growth– meaning a low proportion of births compared to deaths.

In the last 30 years, Canada's population has increased by 32.4 per cent. But the Atlantic provinces have seen their populations edge up by only 3.5 per cent. Meanwhile, Alberta has recorded an increase of 50.8 per cent since 1983.

Also during the last three decades, the population of Ontario has grown almost twice as rapidly as that of Quebec -- 39.8 per cent versus 21 per cent.

Statistics Canada says its estimates are based on 2011 Census counts with numbers adjusted for census net undercoverage (when dwellings and/or individuals are missed), and incompletely enumerated native reserves.