A clinical trial for a new fertility treatment was provided to 250 women for a 10 year study perio~Investigators were interested in noting when women became pregnant for the first time (subsequent pregnancies were not an outcome of interest, only first pregnancies). Every 2 years, they came in for a follow-up visit and were asked if they were pregnant (outcome). Project coordinators also took note at these visits if any of the women had been loss-to-follow-up. Of the 250 women at the beginning of the study, 97 became pregnant by the first visit. During visits 2 and 3, an additional 23 women became pregnant by each visit. Another 15 women became pregnant by the 4th visit, and a final 13 women became pregnant by the last visit. There were also 2 women lost to follow-up at visit 1, 3 women LTFU in visit 2, 4 women LTFU in visit 3, and 16 women LTFU in visit 4. How many person-years are there in this study data?