-0.6% is the change from 664 to 660
Calculation steps:
[( 660 - 664 ) ÷ 664] x 100 = -0.6%
Formula
Percentage change = [(660 - 664) / 664] x 100
Subtract the new number by the original number
660 - 664 = -4
-4 ÷ 664 = -0.006024096385542169
-0.006024096385542169 x 100 = -0.6%