well, don't know about the 70s I wasn't around yet :-P
but now I think numbers are different.. can't really give you an exact percentage but I'm pretty sure most male don't freeball here in Italy
for 2 reason I guess:
- it is widely considered unsanitary (fools!)
- it's still fashionable for many teenagers to show off underwear waistband peekin out from the back
Dolce & Gabbana, Prada, Armani etc etc.. yes Italy has a lot of underwear manifacturers...
I really don't know if freeballing is uncommon here because italian men like wearing fashion underwear or if it is the other way round a lot of underwear manifacturers 'cause italian males don't freeball :-P