-3.02% is the change from 630 to 611
Calculation steps:
[( 611 - 630 ) ÷ 630] x 100 = -3.02%
Formula
Percentage change = [(611 - 630) / 630] x 100
Subtract the new number by the original number
611 - 630 = -19
-19 ÷ 630 = -0.03015873015873016
-0.03015873015873016 x 100 = -3.02%