Broken ROUUNDUP or VLOOKUP formula

Morning!

I have a formula that seems to be working, through much brute force and little finesse. However, one row of the code seems to be broken, and I'm perplexed as to why.

I included a sample file, with the problem row highlighted in yellow. The results of this row should show the number "1" after the person is hired; however, I'm getting the "#N/A" message. The formulas above and below this row seem to work fine. I built the formula in cell D6 and simply copied/pasted down and across.

Any thoughts? Thank you very much, if you do.