-84.77% is the change from 591 to 90
Calculation steps:
[( 90 - 591 ) ÷ 591] x 100 = -84.77%
Formula
Percentage change = [(90 - 591) / 591] x 100
Subtract the new number by the original number
90 - 591 = -501
-501 ÷ 591 = -0.8477157360406091
-0.8477157360406091 x 100 = -84.77%