-97.26% is the change from 657 to 18
Calculation steps:
[( 18 - 657 ) ÷ 657] x 100 = -97.26%
Formula
Percentage change = [(18 - 657) / 657] x 100
Subtract the new number by the original number
18 - 657 = -639
-639 ÷ 657 = -0.9726027397260274
-0.9726027397260274 x 100 = -97.26%