-50.57% is the change from 619 to 306
Calculation steps:
[( 306 - 619 ) ÷ 619] x 100 = -50.57%
Formula
Percentage change = [(306 - 619) / 619] x 100
Subtract the new number by the original number
306 - 619 = -313
-313 ÷ 619 = -0.505654281098546
-0.505654281098546 x 100 = -50.57%