-2.15% is the change from 978 to 957
Calculation steps:
[( 957 - 978 ) ÷ 978] x 100 = -2.15%
Formula
Percentage change = [(957 - 978) / 978] x 100
Subtract the new number by the original number
957 - 978 = -21
-21 ÷ 978 = -0.02147239263803681
-0.02147239263803681 x 100 = -2.15%