Kinsey labeled 1.5% of the adult male population as X. In his second book, Sexual Behavior in the Human Female, he reported this breakdown of individuals who are X: unmarried females = 14–19%, married females = 1–3%, previously married females = 5–8%, unmarried males = 3–4%, married males = 0%, and previously married males = 1–2%.
Kinsey placerede 1,5% af voksne mænd i kategorien X. I sin anden bog, Sexual Behavior in the Human Female (Seksuel adfærd i kvinder) specificerede han andelen af mennesker i kategorien X yderligere: ugifte kvinder = 14-19%, gifte kvinder = 1-3%, tidligere gifte kvinder = 5-8%, ugifte mænd = 3-4%, gifte mænd = 0% og tidligere gifte mænd = 1-2%.