-50.62% is the change from 646 to 319
Calculation steps:
[( 319 - 646 ) ÷ 646] x 100 = -50.62%
Formula
Percentage change = [(319 - 646) / 646] x 100
Subtract the new number by the original number
319 - 646 = -327
-327 ÷ 646 = -0.5061919504643962
-0.5061919504643962 x 100 = -50.62%