-5.89% is the change from 866 to 815
Calculation steps:
[( 815 - 866 ) ÷ 866] x 100 = -5.89%
Formula
Percentage change = [(815 - 866) / 866] x 100
Subtract the new number by the original number
815 - 866 = -51
-51 ÷ 866 = -0.05889145496535797
-0.05889145496535797 x 100 = -5.89%