-88.1% is the change from 664 to 79
Calculation steps:
[( 79 - 664 ) ÷ 664] x 100 = -88.1%
Formula
Percentage change = [(79 - 664) / 664] x 100
Subtract the new number by the original number
79 - 664 = -585
-585 ÷ 664 = -0.8810240963855421
-0.8810240963855421 x 100 = -88.1%