-0.62% is the change from 646 to 642
Calculation steps:
[( 642 - 646 ) ÷ 646] x 100 = -0.62%
Formula
Percentage change = [(642 - 646) / 646] x 100
Subtract the new number by the original number
642 - 646 = -4
-4 ÷ 646 = -0.006191950464396285
-0.006191950464396285 x 100 = -0.62%