How do I find a lit of all the "Items" about a page I can display in Popular Content macro?

[Susan Schaibly]

I'm using the "Popular Content" macro to figure out which of our pages are used the most. In the edit window for the macro, there is a field for "Items to Display" and three item examples are listed: title, icon, count

I'm sure there must be other items I can display, but since there is no drop-down menu, I have no idea what the complete list of item is. I've searched and tried every iteration I can in both the Atlassian documentation and other sources. No luck. 

Does anyone have a complete list of these "items"?