Multiple if functions or vlookup

Hi, I'm trying to make an online amortization calculator for my website.

sample calculator.xlsx

I'm trying to insert value (factor rates) to B27 from specific list depending on the value of Years to pay B10.

I'm trying to use if functions, like I did in B15 but I just couldn't make it work. Also there a problem with B15 since I can't make it percentage instead of decimal.

I would very much appreciate if you could help me. Thank you

In B27 use..

=VLOOKUP(B10,$D$2:$E$11,2,FALSE)

Does this gove you desired results?