-37.33% is the change from 509 to 319
Calculation steps:
[( 319 - 509 ) ÷ 509] x 100 = -37.33%
Formula
Percentage change = [(319 - 509) / 509] x 100
Subtract the new number by the original number
319 - 509 = -190
-190 ÷ 509 = -0.37328094302554027
-0.37328094302554027 x 100 = -37.33%