Dutch research showed that  the number of people who masturbate increases with age:
20% of the girls and 40% of the guys between 11 and 13 years old masturbate.
45% of the girls and 80% of the guys 16 years old masturbate.
Of the adults 55% of the women and 82% of the men masturbate.

As you can see masturbation is very common .