-2.48% is the change from 646 to 630
Calculation steps:
[( 630 - 646 ) ÷ 646] x 100 = -2.48%
Formula
Percentage change = [(630 - 646) / 646] x 100
Subtract the new number by the original number
630 - 646 = -16
-16 ÷ 646 = -0.02476780185758514
-0.02476780185758514 x 100 = -2.48%