-68.71% is the change from 668 to 209
Calculation steps:
[( 209 - 668 ) ÷ 668] x 100 = -68.71%
Formula
Percentage change = [(209 - 668) / 668] x 100
Subtract the new number by the original number
209 - 668 = -459
-459 ÷ 668 = -0.687125748502994
-0.687125748502994 x 100 = -68.71%