-31.6% is the change from 978 to 669
Calculation steps:
[( 669 - 978 ) ÷ 978] x 100 = -31.6%
Formula
Percentage change = [(669 - 978) / 978] x 100
Subtract the new number by the original number
669 - 978 = -309
-309 ÷ 978 = -0.3159509202453988
-0.3159509202453988 x 100 = -31.6%