-19.97% is the change from 646 to 517
Calculation steps:
[( 517 - 646 ) ÷ 646] x 100 = -19.97%
Formula
Percentage change = [(517 - 646) / 646] x 100
Subtract the new number by the original number
517 - 646 = -129
-129 ÷ 646 = -0.1996904024767802
-0.1996904024767802 x 100 = -19.97%