Please see this image (http://i.imgur.com/xZjLD.png) and corresponding code (http://pastebin.com/waHp2WxC)
I'd expect the y axis to run from 0 to 60 as this is the range of the data values, but it runs from 0 to 9.2 and the lines go outside the chart area.
Can the range be set manually?
This is because you're passing the data in as strings, when they need to be numbers. Just drop all the quote marks from your data and you should be fine.