-38.25% is the change from 821 to 507
Calculation steps:
[( 507 - 821 ) ÷ 821] x 100 = -38.25%
Formula
Percentage change = [(507 - 821) / 821] x 100
Subtract the new number by the original number
507 - 821 = -314
-314 ÷ 821 = -0.38246041412911086
-0.38246041412911086 x 100 = -38.25%