-20.47% is the change from 811 to 645
Calculation steps:
[( 645 - 811 ) ÷ 811] x 100 = -20.47%
Formula
Percentage change = [(645 - 811) / 811] x 100
Subtract the new number by the original number
645 - 811 = -166
-166 ÷ 811 = -0.20468557336621454
-0.20468557336621454 x 100 = -20.47%