-98.8% is the change from 831 to 10
Calculation steps:
[( 10 - 831 ) ÷ 831] x 100 = -98.8%
Formula
Percentage change = [(10 - 831) / 831] x 100
Subtract the new number by the original number
10 - 831 = -821
-821 ÷ 831 = -0.9879663056558363
-0.9879663056558363 x 100 = -98.8%