-23.38% is the change from 509 to 390
Calculation steps:
[( 390 - 509 ) ÷ 509] x 100 = -23.38%
Formula
Percentage change = [(390 - 509) / 509] x 100
Subtract the new number by the original number
390 - 509 = -119
-119 ÷ 509 = -0.2337917485265226
-0.2337917485265226 x 100 = -23.38%