A decrease in the number of break-ins sparked a drop in the severity of overall crime in a 10-year-period, while the seriousness of violent crimes remained stable, according to a new report by Statistics Canada.

The agency used a new crime index, which tracks changes in the severity of police-reported crime. It assigns each offence a weight, with more serious crimes like break-ins and robberies assigned higher weights. Statistics Canada says it is the first index of its kind anywhere.

The Police-reported Crime Severity Index is a new tool that Statistics Canada uses to track changes in the severity of crime. The overall severity of crime in 2006 (the base year) is set at 100.

Crimes in the index are given different weights, from marijuana possession (7) and disturbing the peace (9) to manslaughter (1,822) and murder (7,042).

The traditional police-reported crime rate is the number of criminal reports per 100,000 people, and all crimes are given equal weight.

According to the index, overall crime severity fell by about 20 per cent from 1998 to 2007, driven by a 40 per cent drop in break-ins, said the report. Crime fell every year, except for 2003, according to the index.

But the violent crime severity index, which measures crimes such as homicide, robberies and sexual assault, remained relatively stable, with only a two per cent drop.

The index found that overall crime severity fell in every province during the 10-year period, with the largest declines in Ontario and Quebec.

Among the provinces, Manitoba recorded the highest severity of violent crime, followed by Saskatchewan and British Columbia. Saskatchewan actually had a higher violent crime rate than Manitoba — 2,623 reported crimes per 100,000 people compared to 1,986 — but the new index shows that Manitoba has a higher violent crime severity.

In terms of overall crime, Saskatchewan had the highest rate and the highest severity, followed by Manitoba and British Columbia.

Ontario and Quebec had the lowest crime rates in 2007 — the latest year for which figures are available — while the lowest crime severity indexes were in P.E.I. and New Brunswick.

Among Canadian cities, Regina had the highest crime severity in 2007, around twice the national average, followed by Saskatoon and Winnipeg.

Toronto had the lowest crime severity index of the 27 cities surveyed, well below the national average. Vancouver's index was above the national average and the sixth highest of the surveyed metropolitan areas.

 With files from The Canadian Press