-90.33% is the change from 838 to 81
Calculation steps:
[( 81 - 838 ) ÷ 838] x 100 = -90.33%
Formula
Percentage change = [(81 - 838) / 838] x 100
Subtract the new number by the original number
81 - 838 = -757
-757 ÷ 838 = -0.9033412887828163
-0.9033412887828163 x 100 = -90.33%