LONDON – The percentage of British women who have experienced a lesbian encounter has quadrupled during the past 20 years, according to a new national survey conducted by a multi-disciplinary team of researchers.

Among the results of the most recent National Survey of Sexual Attitudes and Lifestyles (Natsal): 8 percent of British women have experienced full-genital-contact lesbian sex, and 16 percent have experienced a lesbian encounter that did not result in coitus. The study sample included 15,000 Britons.

The first Natsal survey, conducted in 1990-91, reported 2 percent and 4 percent, respectively. A second Natsal report, released in 2002 for the study period 1999-2001, reported 6 percent and 10 percent, respectively.

That’s not all: On average, today’s British women have twice as many sexual partners over a lifetime as they did two decades ago. The current lifetime average is 7.7 partners.

In contrast, five percent of the men surveyed reported having gay sex during the third Natsal period (2010-2012). The figure represents a rise of just one percent from 20 years ago. Lifetime male sex partner averages rose from 8.6 in the 1990s to 11.7 now.

“In some areas of sexual behaviour we have seen a narrowing of the gender gap, but in others we have seen women overtaking men in the diversity of their behaviour,” said Professor Kaye Wellings of the London School of Hygiene and Tropical Medicine, one of the participating research organizations.

The changes reported should be viewed “against the backdrop of the profound changes in the position of women in society, the norms governing their lifestyles and media representations of female sexuality,” she said.

More Natsal data: The average Brit is having sex less than five times a month now, compared to six times a month 10 years ago. One in four respondents who are in a relationship now do not share the same level of interest in sex as their partner, and one in five said their partner had experienced “sexual difficulties” within the past year.

Natsal surveys are among the largest and most detailed studies of sexual behaviour in the world. Natsal-1 was conducted in response to an urgent need for information about sexual practices in the context of the HIV/AIDS epidemic; however, the data proved important for a much wider range of public health and wellness concerns. Two subsequent Natsal surveys, conducted at 10-year intervals, expanded the scope of the research and its applications.

The project is managed by researchers from University College London, the London School of Hygiene & Tropical Medicine and National Center for Social Research.

Complete results from all three Natsal sex surveys may be found on Natsal.ac.uk.