How might I write an inverted percentile with critfail, fail, success and critsuccess

I admit to not quite being a brilliant man. The solution to my question might be around here. Hell, I may have looked it right in the eyes and still not noticed. Please don't bite me, snake.

So one of the new systems I am looking to learn to GM lately is Star Trek FASA. It runs off a percentile system that references your character sheet but nothing external really. So your skill with archaic weapons is 55. You roll your percentfile. Anything 1-5 is a crit success, 6-55 is a success, 56-95 is a failure and 96-100 is a crit failure.