-97.93% is the change from 820 to 17
Calculation steps:
[( 17 - 820 ) ÷ 820] x 100 = -97.93%
Formula
Percentage change = [(17 - 820) / 820] x 100
Subtract the new number by the original number
17 - 820 = -803
-803 ÷ 820 = -0.9792682926829268
-0.9792682926829268 x 100 = -97.93%