-18.5% is the change from 811 to 661
Calculation steps:
[( 661 - 811 ) ÷ 811] x 100 = -18.5%
Formula
Percentage change = [(661 - 811) / 811] x 100
Subtract the new number by the original number
661 - 811 = -150
-150 ÷ 811 = -0.18495684340320592
-0.18495684340320592 x 100 = -18.5%