Need formula to return back a desired tier based on excel cell

Good afternoon,

I am trying to figure out a formula to return back a desired word (ex. 33% GP, if % is higher than 29%, "5%+") See below what I am trying to do. I have data that is looking at margin rates, and essentially for certain ranges of rates, I want to return a tier. This is what I am trying to do to design a scoring system for customers. See the attached file of what I am trying to do and some example data.

What I would like is a formula that spits out the 'tier', based on the ranges of GP %, then a formula based on that tier, awards points.

But I want to be able to change the Gp % ranges that the formula gets to, to find the 'tier', so it's dynamic and adjustable as we play with what is the right ranges for the points awarded, etc.

Thank you for the help provided and let me know if I can clarify anything to help with this.

Thanks.