" In other words he is saying "Which makes me think that it does not happen often". "Which" refers to the various things that have been said since the question was posed.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
My guess is that it refers back to the question "Does that happen often?" In other words he is saying "Which makes me think that it does not happen often". "Which" refers to the various things that have been said since the question was posed.