-34.15% is the change from 978 to 644
Calculation steps:
[( 644 - 978 ) ÷ 978] x 100 = -34.15%
Formula
Percentage change = [(644 - 978) / 978] x 100
Subtract the new number by the original number
644 - 978 = -334
-334 ÷ 978 = -0.34151329243353784
-0.34151329243353784 x 100 = -34.15%