-39.61% is the change from 866 to 523
Calculation steps:
[( 523 - 866 ) ÷ 866] x 100 = -39.61%
Formula
Percentage change = [(523 - 866) / 866] x 100
Subtract the new number by the original number
523 - 866 = -343
-343 ÷ 866 = -0.3960739030023095
-0.3960739030023095 x 100 = -39.61%