I understand that caves were used on and off over sapiens history. We must be sure to temper our view of 'cave men' as a normal mode of living. Caves preserve artifacts, to a much greater degree than open ground or forests for instance. It can be appealing to imagine they lived in caves routinely. But we have little data on the frequency of sites outside caves - they've washed and weathered away. A true ratio is hard to come up with.