Hiyou can get this report here
http://www.cbsa-asfc.gc.ca/agency-agence/reports-rapports/pia-efvp/atip-aiprp/thr-rav-eng.html
it take 30 days to get it. But remember always get this report before applying not after you have applied or it may delay your application as they say on website. I got this report 2 months before applying. This report shows entries to Canada in their system and all exits records to USA only via land border.
Neverthless its a good idea to get this report to make sure entries to canada are correct as per your record.
One can also order FOIA records for usa trips to make sure entry/exit to usa are same as per your calculation
I've applied to get the FOIA records from the US. Do you have any idea of how long they take to process the request?