-41.22% is the change from 866 to 509
Calculation steps:
[( 509 - 866 ) ÷ 866] x 100 = -41.22%
Formula
Percentage change = [(509 - 866) / 866] x 100
Subtract the new number by the original number
509 - 866 = -357
-357 ÷ 866 = -0.4122401847575058
-0.4122401847575058 x 100 = -41.22%