-10.4% is the change from 173 to 155
Calculation steps:
[( 155 - 173 ) ÷ 173] x 100 = -10.4%
Formula
Percentage change = [(155 - 173) / 173] x 100
Subtract the new number by the original number
155 - 173 = -18
-18 ÷ 173 = -0.10404624277456648
-0.10404624277456648 x 100 = -10.4%