-15.13% is the change from 978 to 830
Calculation steps:
[( 830 - 978 ) ÷ 978] x 100 = -15.13%
Formula
Percentage change = [(830 - 978) / 978] x 100
Subtract the new number by the original number
830 - 978 = -148
-148 ÷ 978 = -0.15132924335378323
-0.15132924335378323 x 100 = -15.13%