Unfortunately, neither does this. The figures show that children taught abstinence-only have a slightly *higher* level of underage pregnancies and STDs than those taught conventional sex ed. The best guess is that they do it just as much as any other kids (human nature being as hard to beat as ever,) but because they believe they're not going to, they're not prepared.
Even more sadly, there's a growing number of kids turning up with STDs who swear they haven't had sex. Either you really can catch it off a toilet seat, or what they've been taught isn't abstinence, it's denial.