I agree with kdaily, but would like to add that many people don't "count" all sexual experiences, especially if maintaining virginity is important. Touching or grinding genitals can spread the virus, penetration is not needed. Of course there is also risk with anal sex, and some risk with oral sex. I am sure this expalins some of the "virgins" with HPV.
To add, Penile cancer is really rare in developed countries.
Sorry I did forget to mention that your doctor should have done a follow up to double check the results.
If you want numbers you'll have to go the expert forum,
I'm not sure what the likey hood of a false positive for HPV would be, But if you were both virgins enter your relationship and have been together for since, then someone went out side the relationship, Highrisk and lowrisk HPV is transmitted through sexual encounters. Again I don't know if you can have a false pos. for HPV... Others are more then able to respond with more info or you can go to the Expert forum for all the percents of your questions.