-71.23% is the change from 73 to 21
Calculation steps:
[( 21 - 73 ) ÷ 73] x 100 = -71.23%
Formula
Percentage change = [(21 - 73) / 73] x 100
Subtract the new number by the original number
21 - 73 = -52
-52 ÷ 73 = -0.7123287671232876
-0.7123287671232876 x 100 = -71.23%