-21.04% is the change from 656 to 518
Calculation steps:
[( 518 - 656 ) ÷ 656] x 100 = -21.04%
Formula
Percentage change = [(518 - 656) / 656] x 100
Subtract the new number by the original number
518 - 656 = -138
-138 ÷ 656 = -0.21036585365853658
-0.21036585365853658 x 100 = -21.04%