Thats cool of you. Considering that you cant measure that in any way. Some falls dont matter if you have a helmet or not your gonna get really hurt.
I always ski with a helmet. Why? Because I know skiing is risky. Key word is "skiing". I know with, or with out a helmet skiing is risky and I can get hurt.
See with out STDs or pregnancy sex isn't risky. However skiing is always risky with a helmet or not.
You can get killed 1,000 different ways other then hitting your head. You fall 20 feet to flat and compress your spine, or you get towed up a rail and then lacerate your liver. Endless things can happen that will seriously hurt you and not to mention the size of shit they do.
Helmet or not your a cold fucker, and that makes it hard for you a make a stable judgment call when other people argue with you.
Soon as you clip your skis on your at risk of getting hurt.