Line graph help

Hey everybody!! So, here's the deal. I have this data, right. And it looks a bit like this:

GraphHelp1.PNG
Imgur Link

The values represented by "-" are points where we have no data. Anyway, when I graph this, I end up with:

GraphHelp2.PNG
Imgur Link

The problem is that I don't want to have the line at 0% for the points where there is no data. I'd rather just have the line not there at all. Now, I know I can leave the cells blank and I can achieve this, but I don't' like the look of the blank cells. I'd rather put some type of symbol to indicate that there is no data for that period. It doesn't have to be "-". Just something where someone viewing it can see that we had no data. Leaving them blank looks like maybe we had data but someone forgot to put it in the sheet.

Thanks everyone!!

Originally Posted by MrShorty

Reference essay: http://peltiertech.com/mind-the-gap-...g-empty-cells/

Probably the first recommendation is going to be to put =NA() into those "blank" cells instead of a text string like "-".

Thank you for the reference!!

Why would I do the =NA() thing? It returns a value of #N/A. I guess that tells the viewer that there is no data. But is there a more functional reason why I'd want that instead of a text string like "No Data" or something?