-20.96% is the change from 811 to 641
Calculation steps:
[( 641 - 811 ) ÷ 811] x 100 = -20.96%
Formula
Percentage change = [(641 - 811) / 811] x 100
Subtract the new number by the original number
641 - 811 = -170
-170 ÷ 811 = -0.2096177558569667
-0.2096177558569667 x 100 = -20.96%