3253.33% is the change from 15 to 503
Calculation steps:
[( 503 - 15 ) ÷ 15] x 100 = 3253.33%
Formula
Percentage change = [(503 - 15) / 15] x 100
Subtract the new number by the original number
503 - 15 = 488
488 ÷ 15 = 32.53333333333333
32.53333333333333 x 100 = 3253.33%