How many May-December (age difference) relationships have you seen in real life?

okay so im not talking about celebs but actual people you know in real life. i'm 19 and my bf is 52. we have an age difference of 33 years. ive never actually met another couple with an extreme age difference like us. all my parents friends, my friends parents, my bf's friends, and everyone i know , most people are married to someone their own age. so how common is it?? does anyone have a statistic? like 1 in 100 relationships, etc?? thanks