fraction looks so much smaller at first sight?"
as others pointed out, there is a social-personal definition of disabled that makes a high percentage of such folk un-physically disabled...in fact - without sarcasm - many "here" might be disabled...
the label-definition includes learning disabled, mentally disabled, neurotically disabled, depressed etc, and so can possibly expand to include the majority of the population, which might happen if the disability marketing schemes for products and institutions to deal with said disabilities grows...
not to disparage the physically disabled in any way, but simply to acknowledge that this system deals with such things in part by helping, and in greater part by expanding the market to be helped...capitalism creates new disabilities every day, whether they exist or not, in order to market products and drugs - especially drugs - to deal with them. fs