-87.88% is the change from 990 to 120
Calculation steps:
[( 120 - 990 ) ÷ 990] x 100 = -87.88%
Formula
Percentage change = [(120 - 990) / 990] x 100
Subtract the new number by the original number
120 - 990 = -870
-870 ÷ 990 = -0.8787878787878788
-0.8787878787878788 x 100 = -87.88%