Negetive Values in Y Axis

I am seeing -ve values in Y-Axis, although I do not have any -ve values in my data set.
I have a row data and I am trying to draw a timeseries graph.
[['2016-6-1',1330,20],
['2016-6-2',1222,21],
['2016-6-3',1111,33]]

I have the following definition for y axis:
y: {
min:0,
label:"Count"
}

In the Y-Axis I see values like -100 as the first value.

Now, this happens for only a few datasets and not all. But this is very much reproducible.
I can provide the exact dataset if required. Thanks.