https://www.nsopw.gov/en/Education/FactsStatistics

据灯塔国DOJ： 
Research conducted by the Centers for Disease Control (CDC) estimates that approximately1 in 6 boys and 1 in 4 girls are sexually abused before the age of 18.

CDC研究估计： 
美国4个女孩里有一个女孩在18岁之前会被性侵。 
美国6个男孩里有一个男孩在18岁之前会被性侵。

这与灯塔国一媒体报道是吻合的： 
http://www.theatlantic.com/national/archive/2013/01/america-has-an-incest-problem/272459/

One in three-to-four girls, and one in five-to-seven boys are sexually abused before they turn 18, an overwhelming incidence of which happens within the family.

美国3到4个女孩里有一个女孩在18岁之前会被性侵，绝大多数是被自己的家庭成员。 
美国5到7个男孩里有一个男孩在18岁之前会被性侵，绝大多数是被自己的家庭成员。