-39.26% is the change from 866 to 526
Calculation steps:
[( 526 - 866 ) ÷ 866] x 100 = -39.26%
Formula
Percentage change = [(526 - 866) / 866] x 100
Subtract the new number by the original number
526 - 866 = -340
-340 ÷ 866 = -0.39260969976905313
-0.39260969976905313 x 100 = -39.26%