-49.05% is the change from 630 to 321
Calculation steps:
[( 321 - 630 ) ÷ 630] x 100 = -49.05%
Formula
Percentage change = [(321 - 630) / 630] x 100
Subtract the new number by the original number
321 - 630 = -309
-309 ÷ 630 = -0.49047619047619045
-0.49047619047619045 x 100 = -49.05%