9) B

Total number of incidences of breast cancer = 361 + 65 = 426 cases

We can use approximate values for the estimated person-years lived.
So total number of person-years lived = 153400 + 20000 = 173,400 years
Number of 1000 years = 173,300 / 1000 = 173.4 ~ 170

426 / 170 ~ 425 / 170 ~ 2.5

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