-33.95% is the change from 978 to 646
Calculation steps:
[( 646 - 978 ) ÷ 978] x 100 = -33.95%
Formula
Percentage change = [(646 - 978) / 978] x 100
Subtract the new number by the original number
646 - 978 = -332
-332 ÷ 978 = -0.3394683026584867
-0.3394683026584867 x 100 = -33.95%