-16.74% is the change from 866 to 721
Calculation steps:
[( 721 - 866 ) ÷ 866] x 100 = -16.74%
Formula
Percentage change = [(721 - 866) / 866] x 100
Subtract the new number by the original number
721 - 866 = -145
-145 ÷ 866 = -0.1674364896073903
-0.1674364896073903 x 100 = -16.74%