while I am not sure of the number, my guess is over 90% of Indians living in India squat to relieve their bowels. Its considered healthy and its also considered to be more hygenic.
A large proportion of urban city homes have "indian style " potties and most publice toilets will have a majority of such potties. The "Stand up" or "western style" potty or the "throne" is another one of our modernisation globalisation issues.