Spreadsheet Show Vacation Time

I am trying to create a spreadsheet that will show vacation time; accrued, taken, leftover. There are different accrual rates for years of service, and caps on carryover.

I have been trying to figure this out, however the accruals for employees over 1 year are higher than they should be.

Breakdowns are as follows:
1-2 years - 1 week vacation - 40 hours eligible for carryover each year
3-4 years - 2 weeks vacation - 80 hours eligible for carryover each year
5-9 years - 3 weeks vacation - 120 hours eligible for carryover each year
10+ year - 4 weeks vacation - 160 hours eligible for carryover each year