The cleanup after angry workers barricaded the Aradco Management Inc. parts plant in Windsor, Ont., in March after 80 workers at the company and a sister operation were given permanent layoff notices. (Sarah Fraleigh/The Canadian Press)

The crash in auto and parts manufacturing has driven the capacity utilization of Canadian factories to the lowest level since the numbers were first collected in 1987, Statistics Canada said Thursday.

Capacity utilization is the ratio of actual industrial output to potential output.

In the auto assembly and parts industries, "numerous plants reported extended closures and slowdowns in January in reaction to lower demand in Canada and the United States," the agency said.

With the auto industry weakness, capacity utilization in Canada fell 5.6 percentage points to 69.3 per cent in the first quarter.

It was the first time the ratio fell below 70 per cent since the start of the data series in 1987, Statistics Canada said.

Capacity utilization in transportation equipment, including autos, fell 15.8 points from the fourth quarter of 2008 to 42.5 and is now 35 percentage points below the first quarter of 2008.

Construction and mining (excluding oil and gas extraction) were singled out as being especially weak, although 18 of the 21 major industries in the manufacturing group reported drops.

In mining, utilization fell 14.8 percentage points from the fourth quarter to 55.3 per cent, with declines in output of potash, copper, nickel and iron ore.

Rates increased in food manufacturing, beverage and tobacco product manufacturing, and petroleum and coal product manufacturing, Statistics Canada said.