It comes down to the data you have for the chart in SSRS to work on. Having the data in a denormalised format (jan, feb, mar etc) means that the chart does not have a single column that holds the value to represent. If the query was to be in a normalised format then the chart would be easy.

Get the query output the data as shown below.

Year | MonthName | MonthNumber | ValueToShow

Create a chart and set the value as value to show and the category as MonthNumber. Add the year to the series. Change the category label to MonthName, this will order the x values by MonthNumber but show the MonthName.

Fitz