-83.76% is the change from 671 to 109
Calculation steps:
[( 109 - 671 ) ÷ 671] x 100 = -83.76%
Formula
Percentage change = [(109 - 671) / 671] x 100
Subtract the new number by the original number
109 - 671 = -562
-562 ÷ 671 = -0.8375558867362146
-0.8375558867362146 x 100 = -83.76%