The percentage of high school students (grades 9 through 12) who reported ever having had sexual intercourse decreased between 1991 and 2009. In 2009, some 46 percent each of male and female high school students reported having had sexual intercourse, compared with 57 and 51 percent, respectively, in 1991. The percentage of female high school students who used birth control pills during their last sexual intercourse did not measurably change between 1991 and 2009 (25 vs. 23 percent). In contrast, the percentages of high school students who used a condom during their last sexual intercourse increased between 1991 and 2009 (from 55 to 69 percent for males and from 38 to 54 percent for females). The percentage of students who reported being sexually active in the past 3 months fluctuated between 1991 and 2009, with a low of 33 percent of students in 2001. There was no measurable change over time in the percentage of high schools students who drank alcohol or used drugs during their last sexual intercourse.
While reported levels of lifetime and current sexual activity did not vary by sex in 2009, other patterns of sexual behavior did differ. For example, in 2009, a greater percentage of male high school students (26 percent) reported drinking alcohol or using drugs during sex than female high school students (17 percent). In addition, more males than females reported using a condom during their last sexual intercourse (69 vs. 54 percent), while more females than males reported relying on birth control pills (23 vs. 17 percent).