-3.47% is the change from 518 to 500
Calculation steps:
[( 500 - 518 ) ÷ 518] x 100 = -3.47%
Formula
Percentage change = [(500 - 518) / 518] x 100
Subtract the new number by the original number
500 - 518 = -18
-18 ÷ 518 = -0.03474903474903475
-0.03474903474903475 x 100 = -3.47%