-8.51% is the change from 646 to 591
Calculation steps:
[( 591 - 646 ) ÷ 646] x 100 = -8.51%
Formula
Percentage change = [(591 - 646) / 646] x 100
Subtract the new number by the original number
591 - 646 = -55
-55 ÷ 646 = -0.08513931888544891
-0.08513931888544891 x 100 = -8.51%