-50.36% is the change from 836 to 415
Calculation steps:
[( 415 - 836 ) ÷ 836] x 100 = -50.36%
Formula
Percentage change = [(415 - 836) / 836] x 100
Subtract the new number by the original number
415 - 836 = -421
-421 ÷ 836 = -0.5035885167464115
-0.5035885167464115 x 100 = -50.36%