-40.18% is the change from 866 to 518
Calculation steps:
[( 518 - 866 ) ÷ 866] x 100 = -40.18%
Formula
Percentage change = [(518 - 866) / 866] x 100
Subtract the new number by the original number
518 - 866 = -348
-348 ÷ 866 = -0.4018475750577367
-0.4018475750577367 x 100 = -40.18%