In particular, since they were interested in problems reported in the past 12 months, they excluded people who returned their questionnaire who reported they'd been celibate for 12 months or more. This includes 139 men and 238 women (out of totals of 1410 men and 1749 women). Thus 9.8% of men and 13.6% of women admit they've been sexually abstinent for the past year. Presumably more are celibate than will admit it.
The marital celibacy page quotes Prof. Denise Donnelly as reporting 16% of marriages being celibate, with some caveats about how accurate this number is likely to be.
My point is that celibacy is not that unusual.