Secondary axis line won't appear

[Mtta_Young]

I am working on a simple chart showing birth and death rates on one axis, and migration levels on the secondary axis. I want all three series to appear as lines. The primary axis series appear as they should, but when I format the secondary axis chart type to line, the series disappears. If I change the secondary to a different format, (clustered column, etc.) all appear as they should. I've had no success formatting the secondary data series (ie, all the line formatting settings are correct, it just doesn't appear). The image I've included here shows the two line series, with the secondary series in the marked line format: the markers appear, but the line does not. If I try to switch things around, and change the primary axis to clustered columns, the secondary axis still will not appear as a line (although all three series will appear if they are all columns). I've tried enabling the hidden/empty cell option, but that didn't work. Thank you in advance for any solutions.

 

[Jon Peltier]

Right click the chart, choose Select Data from the pop up menu. Click the Hidden and Empty Cells button, and choose to interpolate (draw a line) between points when there is an empty cell.