(c) A member who first becomes a member of the correctional state employees retirement plan after June 30, 2010, is vested at the following percentages when the person has accrued credited allowable service as defined under section 352.01, subdivision 11, as follows:

1. (i) 50 percent after five years;
2. (ii) 60 percent after six years;
3. (iii) 70 percent after seven years;
4. (iv) 80 percent after eight years;
5. (v) 90 percent after nine years; and
6. (vi) 100 percent after ten years.