-91.31% is the change from 990 to 86
Calculation steps:
[( 86 - 990 ) ÷ 990] x 100 = -91.31%
Formula
Percentage change = [(86 - 990) / 990] x 100
Subtract the new number by the original number
86 - 990 = -904
-904 ÷ 990 = -0.9131313131313131
-0.9131313131313131 x 100 = -91.31%