-85.22% is the change from 609 to 90
Calculation steps:
[( 90 - 609 ) ÷ 609] x 100 = -85.22%
Formula
Percentage change = [(90 - 609) / 609] x 100
Subtract the new number by the original number
90 - 609 = -519
-519 ÷ 609 = -0.8522167487684729
-0.8522167487684729 x 100 = -85.22%