How to capture ChartCategoryAxisItem label click?

Hello,

I have a stacked bar chart, basically the same as your Demo - Stacked Bars (Olympic Medals won by USA). In my application I need to perform actions when a user clicks on the ChartCategoryAxisItem label - a year, in this case.

Having had a look at the API doc I haven't found anything suitable - is there a handle that I can hook into to capture that click?

Thankyou