-17.8% is the change from 646 to 531
Calculation steps:
[( 531 - 646 ) ÷ 646] x 100 = -17.8%
Formula
Percentage change = [(531 - 646) / 646] x 100
Subtract the new number by the original number
531 - 646 = -115
-115 ÷ 646 = -0.1780185758513932
-0.1780185758513932 x 100 = -17.8%