-97.41% is the change from 811 to 21
Calculation steps:
[( 21 - 811 ) ÷ 811] x 100 = -97.41%
Formula
Percentage change = [(21 - 811) / 811] x 100
Subtract the new number by the original number
21 - 811 = -790
-790 ÷ 811 = -0.9741060419235512
-0.9741060419235512 x 100 = -97.41%