“In the real world how many people know precisely the day they will become sexually active?”
Most people in the real world wait for marriage, or they get their partner tested.
As for the source, the data is from VEARS.
If your partner gets a clean bill of health from a typical STD test done by a clinic or primary care doc, it will not include HPV. You won’t know that your new spouse had it until oh, about 4-6 months later.
And then you’d better hope your spouse doesn’t stray and bring back something you’ll have to live with for the rest of your life. The sad fact is that half of marriages today end in divorce, and a large percentage of those involve infidelity.