-91% is the change from 200 to 18
Calculation steps:
[( 18 - 200 ) ÷ 200] x 100 = -91%
Formula
Percentage change = [(18 - 200) / 200] x 100
Subtract the new number by the original number
18 - 200 = -182
-182 ÷ 200 = -0.91
-0.91 x 100 = -91%
Example