-39.11% is the change from 836 to 509
Calculation steps:
[( 509 - 836 ) ÷ 836] x 100 = -39.11%
Formula
Percentage change = [(509 - 836) / 836] x 100
Subtract the new number by the original number
509 - 836 = -327
-327 ÷ 836 = -0.3911483253588517
-0.3911483253588517 x 100 = -39.11%