Sentence:  It is significant that the Catskills , which used to be the summer playground for older teen-agers , a kind of summer suburb of New York , no longer attracts them in great <WSD>numbers</WSD> - except for those who work there as waiters , bus boys , or counselors in the day camps . 
Meaning of the word marked with <WSD> tags:  the property possessed by a sum or total or indefinite quantity of units or individuals