71.43% is the change from 21 to 36
Calculation steps:
[( 36 - 21 ) ÷ 21] x 100 = 71.43%
Formula
Percentage change = [(36 - 21) / 21] x 100
Subtract the new number by the original number
36 - 21 = 15
15 ÷ 21 = 0.7142857142857143
0.7142857142857143 x 100 = 71.43%