-4.13% is the change from 509 to 488
Calculation steps:
[( 488 - 509 ) ÷ 509] x 100 = -4.13%
Formula
Percentage change = [(488 - 509) / 509] x 100
Subtract the new number by the original number
488 - 509 = -21
-21 ÷ 509 = -0.0412573673870334
-0.0412573673870334 x 100 = -4.13%