-0.16% is the change from 621 to 620
Calculation steps:
[( 620 - 621 ) ÷ 621] x 100 = -0.16%
Formula
Percentage change = [(620 - 621) / 621] x 100
Subtract the new number by the original number
620 - 621 = -1
-1 ÷ 621 = -0.001610305958132045
-0.001610305958132045 x 100 = -0.16%