This is the formula in a cell which is plotted as a data point on a chart

=IF(B12=0,"",(100-(B13/(SUM(B12:B13))*100)))

It works fine, but I don't want the chart to plot it if the cell is blank ("")
I went into Tools - Options - Chart and selected Plot Empty Cells As Not
plotted
But it still plots the empty cell as zero
Please advise