-40.88% is the change from 866 to 512
Calculation steps:
[( 512 - 866 ) ÷ 866] x 100 = -40.88%
Formula
Percentage change = [(512 - 866) / 866] x 100
Subtract the new number by the original number
512 - 866 = -354
-354 ÷ 866 = -0.40877598152424943
-0.40877598152424943 x 100 = -40.88%