Last tick mark label be cut on Y-Axis


#1

I create a UIView in storyboard, then I put a chart view into the UIView.

when chart view title is empty, last tick mark label be cut on Y-Axis, follow the figures.

How can I fix it, please help me.

here is not empty chart title

Here is source code: 

https://dl.dropboxusercontent.com/u/16971098/ColumnSeries.zip