Wastewater treatment assets in Manitoba have been traditionally older than that of other provinces. The average age went through peaks and troughs since the seventies from a low of 14.0 years in 1970 to a high of 18.9 years in 2004 in response to investment swings. The age averaged 18.5 years in 2007, down slightly from the 2004 peak. As a percentage of estimated useful life, Manitoba has tended to be above the national average in most years. In 2007, the ratio was 66% provincially compared with 63% nationally.