-90.18% is the change from 866 to 85
Calculation steps:
[( 85 - 866 ) ÷ 866] x 100 = -90.18%
Formula
Percentage change = [(85 - 866) / 866] x 100
Subtract the new number by the original number
85 - 866 = -781
-781 ÷ 866 = -0.9018475750577367
-0.9018475750577367 x 100 = -90.18%