Please help me write a formula that calculates the percent change when:

The current result is 11%

The prior result is -1.89%

I am attempting to compare the current result improvement to the prior
result, hence my formula is:

(11%--1.89%)/-1.89% (the calculated result is -682.01%)

The result should be positive, like 1000% change (improvement), shouldn't it
be?

Thanks for helping me with this formula.

Sony