Some 16 percent of girls had sex with male partners who were 4-6 years older and 11 percent had partners that were 7 or more years older.
According to the NCHS's William Mosher, the average age for first-time sex for women is between 16 and 17.
The teenagers didn't believe they were being exploited, and no one reported feeling like a victim.
Among the perceived benefits of their relationships were admiration from their peers and their partner's material assets.
The girls stressed the emotional pluses even more, saying that their older partners were more considerate of their feelings and made them feel special.