3258.33% is the change from 12 to 403
Calculation steps:
[( 403 - 12 ) ÷ 12] x 100 = 3258.33%
Formula
Percentage change = [(403 - 12) / 12] x 100
Subtract the new number by the original number
403 - 12 = 391
391 ÷ 12 = 32.583333333333336
32.583333333333336 x 100 = 3258.33%