-33.2% is the change from 509 to 340
Calculation steps:
[( 340 - 509 ) ÷ 509] x 100 = -33.2%
Formula
Percentage change = [(340 - 509) / 509] x 100
Subtract the new number by the original number
340 - 509 = -169
-169 ÷ 509 = -0.3320235756385069
-0.3320235756385069 x 100 = -33.2%