-97.3% is the change from 667 to 18
Calculation steps:
[( 18 - 667 ) ÷ 667] x 100 = -97.3%
Formula
Percentage change = [(18 - 667) / 667] x 100
Subtract the new number by the original number
18 - 667 = -649
-649 ÷ 667 = -0.9730134932533733
-0.9730134932533733 x 100 = -97.3%