Repayment Rate for Institutions

**User Story**
As a ministry user, every year I need to add a repayment rate for each location code for BC Public and BC Private Institutions `will verify again, initial requirements are for BC institutions`. I also need to save this historical information for reporting reasons.

**Acceptance Criteria**
- [ ] Input a repayment rate that is specific to each location of an institution for a specific year.
- [ ] Edit the repayment rate for a specific year for a specific location.