According to the U.S. Centers for Disease Control and Prevention, 96 percent of Americans over the age of 20 have had sex.

This is just one of the findings in a report issued Friday by the CDC's National Center for Health Statistics about American's sexual behavior and drug use.

The report uses data collected from 1999 to 2002 from 6,237 people aged 20 to 59. Participants submitted computer-assisted self-interviews about the use of cocaine, crack, freebase, and other street drugs, but marijuana was not included. Sexual behavior was defined as vaginal, oral or anal sex.

In previous federal surveys on these topics, participants were asked questions in face-to-face interviews; the CDC believes that caused underreporting of behaviors that might be viewed negatively.

"This is the first time we've used this technique," said Dr. Kathryn Porter, who served as medical officer for the survey. "The participants have a headset on, they hear questions, they touch the screen with responses. There's no one else in the room and they can take as long as they want."

Porter said the findings would provide grist for further studies, notably on the prevalence and patterns of sexually transmitted diseases.

Highlights from the report include:

• Twenty-nine percent of men reported 15 or more female sexual partners in a lifetime compared with 9 percent of women who reported having 15 or more male sexual partners in a lifetime.

• Of all race or ethnic groups, Mexican Americans had the highest percentage of persons never having sex at almost 12 percent.

• Sixteen percent of adults first had sex before the age of 15.

• Only 6 percent of non-Hispanic black persons abstained from sex until age 21 years and older compared with 17 percent for Mexican Americans and 15 percent for non-Hispanic white persons.

• The proportion of adults who first had sex before the age of 15 was highest for persons with less than a high school education

• The median number of lifetime female sexual partners for men was seven and the median number of lifetime male sexual partners for women was four.

• One out of every five adults between 20 and 59 has tried cocaine or street drugs sometime in their life.

• Non-Hispanic white persons had a higher percentage of ever using cocaine or other street drugs while non-Hispanic black persons had a higher percentage of past year use.

• Married adults were less likely to have used cocaine or other street drugs in their lifetime or in the past year.

Click here to view the entire report.

The Associated Press contributed to this report.