Hi there

I am looking to make a simple vertical bar chart based on a pivot table which will show me whether a numerical result this month is or worse than the previous month. I want to show and improvement on the previous month above the line and a reduction below the line. I'm guessing the line value has to be the yearly average so far or something like that but I'm not sure? I'd like to use it to identify a trend such as number of falling months in a row or improving months.

I've seen images of this before but now I am looking for it I cant find anything, would probably help if I knew what this chart type was called?

Thanks for any help
Dex