1977.5% is the change from 40 to 831
Calculation steps:
[( 831 - 40 ) ÷ 40] x 100 = 1977.5%
Formula
Percentage change = [(831 - 40) / 40] x 100
Subtract the new number by the original number
831 - 40 = 791
791 ÷ 40 = 19.775
19.775 x 100 = 1977.5%
Example