The most recent data from the Youth Risk Behavior Surveillance (YRBS) survey indicate that there has been a dramatic decline in the percentage of high school students who have ever had sex in the last two years—from 47% in 2013 to 41% in 2015. Other measures of sexual activity and sexual risk taking also indicate that there has been a decline in overall sexual activity. In 2015, 30% of students reported having sex in the past three months; 12% of students reported that they had ever had sex with four or more partners; and 4% reported that they had ever had sex before age 13.
The YRBS is a nationally representative survey of high school students across thirty-three states , and it is clear that there are wide variations in sexual behavior by state. Looking at just the percentage of students who have ever had sex, values range from 30% in New York to 48% in Mississippi (see map). The data also indicates that the percentage of students who have ever had sex increases from 24% in 9th grade to 58% in 12th grade. Nearly half of 12th grade students (46%) reported that they have had sex in the past three months compared to less than a quarter (16%) of 9th grade students.
The survey also included questions about contraceptive method use. Overall, 14% of sexually active students reported not using a method to prevent pregnancy the last time they had sex.