Who's having sex? And who's having sex with whom?

These are the questions answered in a report issued today (Mar. 3) by the Centers for Disease Control and Prevention's National Center for Health Statistics, based on interviews conducted between 2006 and 2008 with 13,500 men and women between the ages of 15 to 44. The findings may surprise you.

Chastity is trendy

More and more young people are abstaining. No less than 27 percent of 15- to 24-year-old men have never had any form of sexual contact (oral, vaginal, or anal) with another person, up from 22 percent in 2002. Meanwhile, 29 percent of females in that age bracket have never had sex, also up from 22 percent at the time of the last study.

The biggest increase in virginity was seen among 15- to 19-year-olds.

Eventually, though, they'll take the plunge: The survey found that almost everyone between the ages of 25 and 44 has had sex. About 98 percent of females and 97 percent of males in that range have had vaginal intercourse, 89 percent of females and 90 percent of men have had oral sex with an opposite-sex partner, and 36 percent of females and 44 percent of males have had anal sex with an opposite-sex partner.

Females looking both ways

Similar percentages of surveyed men and women identified as either straight or homosexual. However, women were three times more likely than men to identify as bisexual.

Women aged 15 to 44 were more than twice as likely to have had same-sex experiences as men of the same age: Approximately 12.5 percent of women reported at least one such experience compared with only 5.2 percent of men.

According to Anjani Chandra, a health scientist at the NCHS and lead author of the study, these homosexual experiences aren't just incidences of experimentation among college girls. "[We] didn't see anything to support that. We saw the opposite," Anjani told the press.

"When we look at college-degreed women, they were less likely to report same-sex activity than other educational groups. Among men, there’s more same-sex activity among higher-educated men. And for women, the highest level of same-sex activity was reported by those with less education," she said.

This article was provided by Life's Little Mysteries, a sister site to LiveScience. Follow Natalie Wolchover on Twitter @nattyover