-37.03% is the change from 821 to 517
Calculation steps:
[( 517 - 821 ) ÷ 821] x 100 = -37.03%
Formula
Percentage change = [(517 - 821) / 821] x 100
Subtract the new number by the original number
517 - 821 = -304
-304 ÷ 821 = -0.3702801461632156
-0.3702801461632156 x 100 = -37.03%