How to get the bar names from Google Chart api

I am stuck for a couple of days!
I making an app that show cat breeds and when they are discovered in europe.

This is my code:

Since I can't post my code here because the forum want to reformat it.
Check my Google drive:
My code
http://ift.tt/1OeOsCZ

And It returns a good looking chart that looks like this:

What I trying to do is getting the name that's inside a bar of the timeline. As an example, if I click on "pers(ion)" , I want to make dynamicaly a div with more information about the pers(ion). But because it doesn't get a class or id I can't get it.

Does anybody now an easy way do do this?