-2.33% is the change from 515 to 503
Calculation steps:
[( 503 - 515 ) ÷ 515] x 100 = -2.33%
Formula
Percentage change = [(503 - 515) / 515] x 100
Subtract the new number by the original number
503 - 515 = -12
-12 ÷ 515 = -0.02330097087378641
-0.02330097087378641 x 100 = -2.33%