Sentence:  Thus it appears, that the greatest number of cases of uterine cancer occurs between the ages of 30 and 40, and 40 and 45; that nearly equal numbers take place in the first decade, and the latter <WSD>quintade</WSD>; that, nevertheless, if the <WSD>quintades</WSD> of the latter decade be conjoined, very nearly double the number (201) take place in the decade between 40 and 50, of that which takes place in the decade between 30 and 40; that next to the decade between 20 and 40, that between 20 and 30 is most liable; yet that this does not approach the <WSD>quintade</WSD> between 45 and 50; that below the age of 20 the frequency of uterine cancer varies from on-eighth to one-ninth of that of other periods; that after 50 it is about one-fifteenth; and that after 60 it is so low as a twenty-fifth or twenty-sixth. 
Meaning of the word marked with <WSD> tags:  A period of 5 years.