According to the National Center for Health Statistics, Vital and Health Statistics Division data for 1995:

Of 9.7 million women using "coitis-dependent contraceptives"  [i.e. barrier birth control methods such as the condom] in the 3 months prior to the interview, about 33% -- over 3 million -- used them inconsistently. An even higher percentage of teens using these methods reported inconsistent use -- 38%. The highest percentage of any group of women reporting inconsistent use was in the 20-24 year old group -- almost 42%.

9% of sexually active teens under age 16 are using the pill; 33.6% of these teens use condoms.

Nearly 30% of all women who had intercourse in the 3 months prior to the interview and used the pill as the only contraceptive method, reported missing a pill at least once during the cycle. [Table 45]