-3.46% is the change from 866 to 836
Calculation steps:
[( 836 - 866 ) ÷ 866] x 100 = -3.46%
Formula
Percentage change = [(836 - 866) / 866] x 100
Subtract the new number by the original number
836 - 866 = -30
-30 ÷ 866 = -0.03464203233256351
-0.03464203233256351 x 100 = -3.46%