-1.37% is the change from 878 to 866
Calculation steps:
[( 866 - 878 ) ÷ 878] x 100 = -1.37%
Formula
Percentage change = [(866 - 878) / 878] x 100
Subtract the new number by the original number
866 - 878 = -12
-12 ÷ 878 = -0.01366742596810934
-0.01366742596810934 x 100 = -1.37%