Hi Laura,
By law, everything on your credit report must be accurate, complete and verifiable. Thus if you authorized the information to be reported on your Equifax or TransUnion credit report, it can stay on there for 6 years. That's the amount of time that credit bureaus are allowed to report something.
If however the information is not authorized, is inaccurate or incomplete it must be fixed or deleted within a reasonable amount of time. (I hate the word reasonable)
You would have to check out the "Credit Reporting Act" or similar in your province to know what the regulations say about how long credit bureaus can keep your information on file.
Bankruptcies can stay on for 7 years, and double bankruptcies (you declared bankruptcy twice) can stay on for up to 14 years in some provinces of Canada.
The reason credit info stays on your report for six year is to give creditors a reasonable credit history.
The longer the time lapsed, the less relevant the history becomes to your current situation.

