-31.39% is the change from 978 to 671
Calculation steps:
[( 671 - 978 ) ÷ 978] x 100 = -31.39%
Formula
Percentage change = [(671 - 978) / 978] x 100
Subtract the new number by the original number
671 - 978 = -307
-307 ÷ 978 = -0.31390593047034765
-0.31390593047034765 x 100 = -31.39%