-18.89% is the change from 90 to 73
Calculation steps:
[( 73 - 90 ) ÷ 90] x 100 = -18.89%
Formula
Percentage change = [(73 - 90) / 90] x 100
Subtract the new number by the original number
73 - 90 = -17
-17 ÷ 90 = -0.18888888888888888
-0.18888888888888888 x 100 = -18.89%