How to get empty category values on bar chart from MDX query

Hi,

I'm using the following kind of a query in a report:

SELECT {[Measures].[Amount]} ON 0,
NON EMPTY ([Maturity].[Maturity].[Maturity]) ON 1
FROM [Cube]

The Maturity dimension is a date dimension. The query produces the following for year 2015:

2015-03-01    123
2015-06-01    456
2015-07-01    789
2015-12-01    123

This gives me the following kind of chart:

Now, how can I get the X-axis to show every month i.e. 3/2015, 4/2015, 5/2015 etc? I tried fiddling around with empty point properties but didn't get anywhere.