-50.82% is the change from 671 to 330
Calculation steps:
[( 330 - 671 ) ÷ 671] x 100 = -50.82%
Formula
Percentage change = [(330 - 671) / 671] x 100
Subtract the new number by the original number
330 - 671 = -341
-341 ÷ 671 = -0.5081967213114754
-0.5081967213114754 x 100 = -50.82%