-96.73% is the change from 550 to 18
Calculation steps:
[( 18 - 550 ) ÷ 550] x 100 = -96.73%
Formula
Percentage change = [(18 - 550) / 550] x 100
Subtract the new number by the original number
18 - 550 = -532
-532 ÷ 550 = -0.9672727272727273
-0.9672727272727273 x 100 = -96.73%