Excel - Axis data points

I have problems with the x-axis data points and filtering them. It's Excel 2013, column chart.

For the x-axis I have "=Recruitment!$D$13:$Q$13". This are 14 data points. after I marked this section, Excel shows me 37 other (empty) data points (see picture).

How can I get rid of the 37 useless datapoints?

The column chart itself only shows my 14 data points, but if I want to filter some points, I have to un-click the 37 as well as they are appearing in my chart out of the sudden. What kind of bug is it?