-36.95% is the change from 820 to 517
Calculation steps:
[( 517 - 820 ) ÷ 820] x 100 = -36.95%
Formula
Percentage change = [(517 - 820) / 820] x 100
Subtract the new number by the original number
517 - 820 = -303
-303 ÷ 820 = -0.3695121951219512
-0.3695121951219512 x 100 = -36.95%