All we really know for sure is that most men masturbate or have at some point in their life.
Masturbatory frequency really depends on a few things like how accessible privacy is, how much partner sex a man is getting, how healthy a man is, intensity of sex drive and age. All are interrelated as far as a man is concerned.
A man sexually peaks around 20-21, which means he could successfully impregnate many more women that he could say at 30, 40 and so on. Most of that sperm swims down the drain during this time because he is masturbating almost daily.
By the time we are 40, our T levels start to decline and we can impregnate quite a few less women than we could at 20. Our sex drive declines and we masturbate about 1-2-3 times a week, married or not.
I would say a man masturbates on average about 1-5 times a week, depending on his age.
I am over 50, married and have masturbated 2 times so far this week and had sex with my wife once. I am healthy, eat right and exercise regularly so my sex drive might be a little bit high for my age. I am actually masturbating a little more as we age because her desire is not what it used to be.