-1.82% is the change from 660 to 648
Calculation steps:
[( 648 - 660 ) ÷ 660] x 100 = -1.82%
Formula
Percentage change = [(648 - 660) / 660] x 100
Subtract the new number by the original number
648 - 660 = -12
-12 ÷ 660 = -0.01818181818181818
-0.01818181818181818 x 100 = -1.82%