Sex is concentrated within a small, yet sexually active, group of people. In one study, it was reported that the 5 % of the population with the highest number of vaginal sex acts (penile-vaginal-intercourse) accounted for more vaginal sex acts than the bottom 50 % of the population with the lowest number of vaginal sex acts.
https://www.researchgate.net/publication/367325876_Sexual_loneliness_A_neglected_public_health_problem