-97.17% is the change from 635 to 18
Calculation steps:
[( 18 - 635 ) ÷ 635] x 100 = -97.17%
Formula
Percentage change = [(18 - 635) / 635] x 100
Subtract the new number by the original number
18 - 635 = -617
-617 ÷ 635 = -0.9716535433070866
-0.9716535433070866 x 100 = -97.17%