-70.83% is the change from 72 to 21
Calculation steps:
[( 21 - 72 ) ÷ 72] x 100 = -70.83%
Formula
Percentage change = [(21 - 72) / 72] x 100
Subtract the new number by the original number
21 - 72 = -51
-51 ÷ 72 = -0.7083333333333334
-0.7083333333333334 x 100 = -70.83%