For the first time, seniors outnumber children in Canada, as the population experienced its greatest increase in the proportion of older people since Confederation, according to the latest census data.

Statistics Canada's 2016 census figures released Wednesday include demographic data related to age, gender and where Canadians live.

There are now 5.9 million Canadian seniors, compared to 5.8 million Canadians 14 and under.

This is due to the historic increase in the number of people over 65 — a jump of 20 per cent since 2011 and a significantly greater increase than the five per cent growth experienced by the population as a whole.

The minister of families, children and social development says OAS eligibility should still be 65, despite the aging population 0:34

The increase in the share of the oldest Canadians was even bigger — up 19.4 per cent for those over 85 and up 41.3 per cent among those over 100.

The result is the median age of the Canadian population in 2016 increased to 41.2 years, six months older than the median age just five years ago. (Median age is the point that separates an equal number of Canadians who are older and younger.)

The aging of the population is due to the first baby boomers turning 65 over the last five years, as well as the increasing life expectancy of Canadians and a low fertility rate.

Projections suggest the imbalance in the population will only grow.

By 2031, about 23 per cent of Canadians could be seniors, similar to Japan, the world's oldest country.

By 2061, there could be 12 million seniors to just eight million children in Canada.

"As people get older, they need more health care, more home care, and that puts increasing demands on government spending," says Dr. Frances Woolley, economics professor at Carleton University in Ottawa. "There are big challenges for the government coming on the fiscal side."

But Canada is still younger than most of its G7 counterparts. Only the United States has a younger population among the world's biggest industrialized economies.

Nevertheless, the share of Canadians in the labour market (between ages 15 and 64) has decreased since 2011 to 66.5 per cent from 68.5 per cent.

The growth in the number of working Canadians was the lowest since 1851, making its share of the population the smallest in 40 years.

Aging population a political challenge

In 1966, there were twice as many people entering the labour market as there were heading for retirement. Today, however, there are just 4.3 million Canadians between ages 15 and 24, compared to 4.9 million Canadians 55 to 64.

This could put a strain on the government's balance sheet — and force it to make difficult political decisions.

According to Woolley, younger people are increasingly struggling to find well-paid, stable employment. When young workers are not earning an income, they do not pay taxes. This has the potential to decrease the amount of tax revenues going into government coffers just as retiring older Canadians start to dip into their savings — which, if they are Registered Retirement Savings Plans, are taxed.

"Retirees don't want to crack open their nest eggs and share it with the federal government. It makes it politically harder for governments to collect tax revenue going forward."

Woolley calls it a "slow-motion train wreck. People respond quickly and effectively to emergencies and natural disasters, but not to longer-term trends. This conversation has been going on for decades."

Canada’s Minister of Social Development Jean-Yves Duclos on how to government is preparing to handle an aging population 7:23

André Lebel, a demographer with Statistics Canada, says that if the labour activity rate and productivity increase, that could counteract some of the effects of the aging population. Increasingly, older Canadians are staying in the workforce.

"Just because someone reaches the age of 65, that doesn't mean they aren't active anymore."

Seniors now outnumber children in Canada due to aging baby boomers and a decline in fertility, according to Statistics Canada. (Nancy Russell/CBC)

Eastern Canada getting older than the West

At nearly 20 per cent, Atlantic Canada has the highest proportion of seniors in the country, while Alberta, at just over 12 per cent, has the lowest. That disparity between Canada's oldest and youngest regions is the widest in the country's history.

This has partly been driven by economic factors, but also by the fact that the baby boom was more pronounced in Atlantic Canada than in other parts of the country, says Lebel.

Alberta, Saskatchewan and Manitoba, as well as the three northern territories, have more children than seniors. The three prairie provinces also have more millennials (individuals 15 to 34) than baby boomers (51 to 70).

Two municipalities in the Prairies had the highest share of children: 34.4 per cent in Mackenzie County, Alta., and 33.4 per cent in Stanley, Man.

At 27.7 years old, Nunavut had the youngest average age in the country.

The share of the population that is working age has dropped to it lowest level since 1976, and is trending lower. (Census 2016/CBC News)

British Columbia, however, has a demographic profile more similar to the East than to the rest of Western Canada, with some of the oldest communities in the country and an average age of 42.3 years. The four Atlantic provinces had average ages ranging from 42.7 to 43.7, the highest in Canada.

B.C. also has the four municipalities, three of them on Vancouver Island, with the most seniors: Qualicum Beach (52.1 per cent), Parksville (42.4 per cent), Osoyoos (42.9 per cent) and Sidney (40.9 per cent).

Increasingly more women than men

The census also found that women (at 50.9 per cent) continue to outnumber men in the country.

The ratio of women to men increases with age — there are twice as many women over 85 as men. Accordingly, older communities had the greatest imbalances of women to men, while municipalities that are home to ski resorts, correctional facilities or military bases tended to have more men than woman.

Share of single-detached houses continues to drop

At 53.6 per cent, a majority of the 14.1 million occupied dwellings in the country remain single-detached homes, but that share has been declining steadily since the 1980s.

Another 27.9 per cent of dwellings were apartments (primarily those with fewer than five storeys) and 5.6 per cent were duplex apartments. By far, Toronto had the highest share of apartments in buildings of five storeys or more (29.4 per cent), while Montreal, Sherbrooke and Quebec City had the highest share of low-rise apartments (between 37 and 41 per cent).

Due to the aging population, 1.2 per cent of Canadians now live in nursing homes or seniors' residences — a share that Statistics Canada says will increase.