Those figures were for British commercial laying hens, work by Appleby et.al. in the journal British Poultry Science 1992, 1993. In an experimental context, usage of perches varied (from less than 3% to over 40%) with factors like perch design, height and group size.This research is conducted with British commercial layers as wel as different heritage breeds. I presume it is an average, is that right? (The online version only shows 52 pages).
From reading all kind of personal messages from BYC keepers, I concluded it differs for different breeds / different types of chickens.
I also concluded and my own experience confirms this statement : circumstances (like harassment / a mother that teaches her chicks / or a keeper that puts the chicks on a roost at nightfall) do influence their preference.