An aging population means that the portion of workers nearing retirement rose significantly between 2001 and 2006, Statistics Canada said Tuesday.

The federal government agency said that in 2006, workers aged 55 or older made up 15.3 per cent of the total workforce. That was up from 11.7 per cent five years earlier.

"This was the result of the aging of the baby boomers, and the increased tendency for older workers to participate in the labour force," Statistics Canada said.

Saskatchewan had the highest share of workers at least 55 years old, with 18.2 per cent of its workforce in 2006 in that age bracket.

Nunavut had the lowest proportion, with only 10.7 per cent of its workers 55 or older.

The rising proportion of older workers meant that the median age of the labour force surpassed 40 years for the first time. The median — the point where half the workers are younger and half are older — rose from 39.5 years in 2001 to 41.2 years in 2006.

Some observers predict the aging workforce could lead to staffing shortages, as the number of younger workers entering the job market is outstripped by retirees.

While Canada's workforce aged, the number of people employed also rose. Between 2001 and 2006, employment increased by an average annual rate of 1.7 per cent.

Statistics Canada said that growth rate put Canada at the head of the G7 nations, followed by Italy at 1.2 per cent.

Employment rose in every part of the country, and showed the most strength in the West, and especially in Alberta and British Columbia.

The country's mining and oil and gas extraction sectors showed the fastest jobs growth between 2001 and 2006. Those sectors grew at an average pace of 7.5 per cent a year, nearly four times the national average. Alberta accounted for 70 per cent of the employment growth in this industry as strong prices for oil and other commodities provided the fire for the province's economy.

The construction sector grew by a strong 4.5 per cent on average per year, thanks to a period of relatively low interest rates. Over the five-year period, construction employers added about 196,200 workers.

Employment in health care and social assistance grew by 199,900 workers, equal to 2.6 per cent on average each year, while retail sector employment grew by 1.8 per cent a year on average for an overall gain of 155,800 jobs.

The country's manufacturing sector lost 136,700 jobs during the five-year period, equivalent to a 1.4 per cent decline per year.

Central Canada bore the brunt of the job losses, which have occurred as the Canadian dollar appreciated against the U.S. dollar.