-9.5% is the change from 200 to 181
Calculation steps:
[( 181 - 200 ) ÷ 200] x 100 = -9.5%
Formula
Percentage change = [(181 - 200) / 200] x 100
Subtract the new number by the original number
181 - 200 = -19
-19 ÷ 200 = -0.095
-0.095 x 100 = -9.5%
Example