You’re absolutely right, stats are a very misunderstood subject. It’s difficult to contextualize stats like this when the population is so large. My measurement for when I got old was when I started to meet old friends and at some point in the conversation we begin talking about other friends who we both knew who’ve passed away since the last time we’ve talked.
To add to the problem, social security was never meant to be an national ID number. It was just really useful for a whole lot of things. However, numbers are handed out sequentially, not randomly. So take your SIN and add or subtract one from it and that is another person’s SIN. Knowing just a few simple things about a person can reveal most if not their entire SIN.