15.38% is the change from 13 to 15
Calculation steps:
[( 15 - 13 ) ÷ 13] x 100 = 15.38%
Formula
Percentage change = [(15 - 13) / 13] x 100
Subtract the new number by the original number
15 - 13 = 2
2 ÷ 13 = 0.15384615384615385
0.15384615384615385 x 100 = 15.38%