-52.89% is the change from 830 to 391
Calculation steps:
[( 391 - 830 ) ÷ 830] x 100 = -52.89%
Formula
Percentage change = [(391 - 830) / 830] x 100
Subtract the new number by the original number
391 - 830 = -439
-439 ÷ 830 = -0.5289156626506024
-0.5289156626506024 x 100 = -52.89%