Teenage pregnancy is four times as prevalent in the US as in the European Union, but has been steadily declining since 1991, reaching a record low in 2012, according to the US Centers for Disease Control and Prevention (CDC), and continuing to decline through 2017. The CDC said in 2007, 35% of US high school students were currently sexually active and 47.8% of US high school students reported having had sexual intercourse. In 2017, the percentage sexually active was down to 28.7%, and the percentage who had ever had intercourse was 39.5%. According to a 1994 study, every year an estimated one in four sexually active teens contracts a sexually transmitted infection (STI).