How old are you? How many people from your high school years have passed? Say, in your year and the years adjacent, where you might be told the news?

Out of about 90, I can count 4. Graduated 1999. 1 in 200 per year sounds like it might be ballpark, though of course from my limited set it's hard to tell. Assuming the rate is low at around 40 but a fair bit lower when you've just graduated, and a fair bit higher as you pass 60.