-90.3% is the change from 835 to 81
Calculation steps:
[( 81 - 835 ) ÷ 835] x 100 = -90.3%
Formula
Percentage change = [(81 - 835) / 835] x 100
Subtract the new number by the original number
81 - 835 = -754
-754 ÷ 835 = -0.9029940119760479
-0.9029940119760479 x 100 = -90.3%