-88.29% is the change from 666 to 78
Calculation steps:
[( 78 - 666 ) ÷ 666] x 100 = -88.29%
Formula
Percentage change = [(78 - 666) / 666] x 100
Subtract the new number by the original number
78 - 666 = -588
-588 ÷ 666 = -0.8828828828828829
-0.8828828828828829 x 100 = -88.29%