-6.59% is the change from 91 to 85
Calculation steps:
[( 85 - 91 ) ÷ 91] x 100 = -6.59%
Formula
Percentage change = [(85 - 91) / 91] x 100
Subtract the new number by the original number
85 - 91 = -6
-6 ÷ 91 = -0.06593406593406594
-0.06593406593406594 x 100 = -6.59%