-40.84% is the change from 857 to 507
Calculation steps:
[( 507 - 857 ) ÷ 857] x 100 = -40.84%
Formula
Percentage change = [(507 - 857) / 857] x 100
Subtract the new number by the original number
507 - 857 = -350
-350 ÷ 857 = -0.40840140023337224
-0.40840140023337224 x 100 = -40.84%