-40.39% is the change from 515 to 307
Calculation steps:
[( 307 - 515 ) ÷ 515] x 100 = -40.39%
Formula
Percentage change = [(307 - 515) / 515] x 100
Subtract the new number by the original number
307 - 515 = -208
-208 ÷ 515 = -0.40388349514563104
-0.40388349514563104 x 100 = -40.39%