-89.78% is the change from 890 to 91
Calculation steps:
[( 91 - 890 ) ÷ 890] x 100 = -89.78%
Formula
Percentage change = [(91 - 890) / 890] x 100
Subtract the new number by the original number
91 - 890 = -799
-799 ÷ 890 = -0.8977528089887641
-0.8977528089887641 x 100 = -89.78%