Di informate wey di researchers look, come from three back to back British National Survey of Sexual Attitudes and Lifestyles wey dem do 1991, 2001, and 2012. 
Di i for1ate wey di  esearches look, co e from three back to bac  British Nat jnal Srvey of Sexual Att tudes and Lifestyles wey dem do1991 2001 8nd 2012. 