3280% is the change from 15 to 507
Calculation steps:
[( 507 - 15 ) ÷ 15] x 100 = 3280%
Formula
Percentage change = [(507 - 15) / 15] x 100
Subtract the new number by the original number
507 - 15 = 492
492 ÷ 15 = 32.8
32.8 x 100 = 3280%
Example