-1.59% is the change from 630 to 620
Calculation steps:
[( 620 - 630 ) ÷ 630] x 100 = -1.59%
Formula
Percentage change = [(620 - 630) / 630] x 100
Subtract the new number by the original number
620 - 630 = -10
-10 ÷ 630 = -0.015873015873015872
-0.015873015873015872 x 100 = -1.59%