-96.42% is the change from 866 to 31
Calculation steps:
[( 31 - 866 ) ÷ 866] x 100 = -96.42%
Formula
Percentage change = [(31 - 866) / 866] x 100
Subtract the new number by the original number
31 - 866 = -835
-835 ÷ 866 = -0.964203233256351
-0.964203233256351 x 100 = -96.42%