Now I would like to ask you some questions about sexual activity in order to gain a better understanding of how behavior afftects health. Please answer these questions to the best of your knowledge. This information will be completely private; under no circumstances will it be revealed to your partner or anyone else.
How old were you when you first had sexual intercourse? Age in years.
Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.