From the London Telegraph:
The National (UK) Survey of Sexual Attitudes and Lifestyles (Natsal) has been conducted roughly every decade in the UK since 1990. The last one came out in 2011, when it showed sex was in decline. Between 1990 and 2011, the number of times the average Brit was having sex each month had fallen from five to three. [scroll for more:]
In fact, in what may come as alarming news to Generation Z, a Telegraph analysis of YouGov polling shows that young people are now having less sex than their parents. The proportion of 18- to 24-year-olds that are sexually active has declined considerably.