100% is the change from 259 to 518
Calculation steps:
[( 518 - 259 ) ÷ 259] x 100 = 100%
Formula
Percentage change = [(518 - 259) / 259] x 100
Subtract the new number by the original number
518 - 259 = 259
259 ÷ 259 = 1
1 x 100 = 100%
Example