-39.52% is the change from 840 to 508
Calculation steps:
[( 508 - 840 ) ÷ 840] x 100 = -39.52%
Formula
Percentage change = [(508 - 840) / 840] x 100
Subtract the new number by the original number
508 - 840 = -332
-332 ÷ 840 = -0.3952380952380952
-0.3952380952380952 x 100 = -39.52%