Puerto Rico has a significant problem with teen pregnancy, with 19.2% of live births in 2000 being to mothers under 20 years old. This is a higher percentage than in the United States, where teen birth rates have declined since 1991. Factors that contribute to teen pregnancy in Puerto Rico include increased early sexual activity combined with decreased use of contraceptives. Unplanned pregnancies accounted for about 60% of all births in Puerto Rico in 2000, with an even higher percentage among teenage mothers. While San Juan, Bayamon and Ponce had the highest raw numbers of teen births, the towns with the highest percentages relative to total births were Morovis, Loiza, Vieques, Comerio and Sal