1373.33% is the change from 15 to 221
Calculation steps:
[( 221 - 15 ) ÷ 15] x 100 = 1373.33%
Formula
Percentage change = [(221 - 15) / 15] x 100
Subtract the new number by the original number
221 - 15 = 206
206 ÷ 15 = 13.733333333333333
13.733333333333333 x 100 = 1373.33%