-18.18% is the change from 121 to 99
Calculation steps:
[( 99 - 121 ) ÷ 121] x 100 = -18.18%
Formula
Percentage change = [(99 - 121) / 121] x 100
Subtract the new number by the original number
99 - 121 = -22
-22 ÷ 121 = -0.18181818181818182
-0.18181818181818182 x 100 = -18.18%