It may lower everyone's risk of re-offending by making them older when they get out: https://www.statcan.gc.ca/pub/85-002-x/2016001/article/14309... (via https://www.statcan.gc.ca/pub/85-002-x/2016001/article/14309... )

Although I guess it would make more sense to be looking at a chart of 2nd offences.