The number of people in Canada at least 65 years old could outnumber children under 15 for the first time within five years, Statistics Canada said Wednesday.

Seniors attend an adapted yoga class at the Molson Street Concordia Village in Winnipeg. Statistics Canada said Wednesday that Canadians who are at least 65 years old could outnumber children under 15 for the first time within five years. (Wayne Glowacki/Canadian Press)

A report released by the federal agency also said the country's population could top 40 million by 2036, under a low-growth projection.

Under a medium-growth forecast, the national population is projected to rise to 43.8 million, while under a high-grow outlook, the number of people in the country could rise to 47.7 million.

In 2009, Canada had 33.7 million residents.

Statistics Canada said the number of senior citizens is projected to reach between 9.9 million and 10.9 million by 2036, more than double last year's level of 4.7 million.

Seniors would surpass the number of children 14 or under for the first time ever between 2015 and 2021, depending on the growth scenario.

The median age of the population — the point where half the population is younger and half is older —would range between 42 and 45 years, compared to the current median of 39.5.

Proportion of working population shrinks

At the same time, the proportion of the working-age population aged 15 to 64 would decline steadily from about 70 per cent to about 60 per cent by 2036.

The population of every province and territory would increase during this time, except under the low-growth scenario. In that case, Newfoundland and Labrador would be expected to see its population decline.

Regardless of the growth scenario, the population increase would be higher than the national average in Ontario and British Columbia.