100%?

I don't think you factored into this human error, because every single birth control method has a failure rate, and the vast bulk of that rate comes from less than stellar use.  Add in outright dishonesty, like my ex-wife taking herself off birth control and 'neglecting' to tell me, so we ended up pregnant without my consent, and now we're into a totally different ball of wax, aren't we?

Half of all abortions are women under 25, 60% of them are single women.  Speaking anecdotally about my experience back in 1992 with my girlfriend, everyone else at that clinic that day was a teenage girl there with her mother. I was the only male in the place, and I was 22.

The CMA estimates that as high as 40% of pregnancies are unexpected. That's a FAR cry from 100% avoidable, and is a more realistic figure that takes into account human variability in discipline, knowledge, access, etc.