-50.8% is the change from 628 to 309
Calculation steps:
[( 309 - 628 ) ÷ 628] x 100 = -50.8%
Formula
Percentage change = [(309 - 628) / 628] x 100
Subtract the new number by the original number
309 - 628 = -319
-319 ÷ 628 = -0.5079617834394905
-0.5079617834394905 x 100 = -50.8%