-91.62% is the change from 990 to 83
Calculation steps:
[( 83 - 990 ) ÷ 990] x 100 = -91.62%
Formula
Percentage change = [(83 - 990) / 990] x 100
Subtract the new number by the original number
83 - 990 = -907
-907 ÷ 990 = -0.9161616161616162
-0.9161616161616162 x 100 = -91.62%