-51.25% is the change from 642 to 313
Calculation steps:
[( 313 - 642 ) ÷ 642] x 100 = -51.25%
Formula
Percentage change = [(313 - 642) / 642] x 100
Subtract the new number by the original number
313 - 642 = -329
-329 ÷ 642 = -0.5124610591900312
-0.5124610591900312 x 100 = -51.25%