-40.47% is the change from 509 to 303
Calculation steps:
[( 303 - 509 ) ÷ 509] x 100 = -40.47%
Formula
Percentage change = [(303 - 509) / 509] x 100
Subtract the new number by the original number
303 - 509 = -206
-206 ÷ 509 = -0.40471512770137524
-0.40471512770137524 x 100 = -40.47%