Defining the basic operation as the comparison of list elements and ignoring the amount of work required to exchange list elements, write a recurrence relation for the amount of work done by selection sort on an n - element list.

This is a question from Mathematical Strctures for Computer Science 7th editon by Judith L. Gersting section 3.3 #16. In the solution manual from Chegg, it says the answer is T(n) = T(n - 1) + n - 1 for n >= 2 provided by the basis step: T(1) = 0.

Could someone help explain this answer? Thanks!