…is the correct answer to this question.
Depending on what parts we're talking about, the grouping could be '60-'65, '60-'66, '60-'72, '62-'66, '63-'66, '64-'66, '62-'72, '65-'72, '66-'72, '60-'76, '73-'76, '74-'76, '75-'76, and a whole bunch of one-year-onlies. Within all those, it could be...