-83.23% is the change from 990 to 166
Calculation steps:
[( 166 - 990 ) ÷ 990] x 100 = -83.23%
Formula
Percentage change = [(166 - 990) / 990] x 100
Subtract the new number by the original number
166 - 990 = -824
-824 ÷ 990 = -0.8323232323232324
-0.8323232323232324 x 100 = -83.23%