Wrong value in footer row - recommend new formula

I use this Numbers Document as a tempalte.

The table shown in the screenshot shows a value of 1,102. When data fills Column G, that value is correct. When Column G is empty, I would like the total to be 0.

I'm seeking the best formula to address this issue. The current formula I'm using is COUNTIF (Column G," <> 0"). Can anyone provide a more effective formula?