90.48% is the change from 21 to 40
Calculation steps:
[( 40 - 21 ) ÷ 21] x 100 = 90.48%
Formula
Percentage change = [(40 - 21) / 21] x 100
Subtract the new number by the original number
40 - 21 = 19
19 ÷ 21 = 0.9047619047619048
0.9047619047619048 x 100 = 90.48%