-90.1% is the change from 990 to 98
Calculation steps:
[( 98 - 990 ) ÷ 990] x 100 = -90.1%
Formula
Percentage change = [(98 - 990) / 990] x 100
Subtract the new number by the original number
98 - 990 = -892
-892 ÷ 990 = -0.901010101010101
-0.901010101010101 x 100 = -90.1%