Best practices for making a rolling report by month and year

My Rows are by cost code and phase which i need by job. My columns are by Month today. I need to add year to the columns too, as i need the report to continue to expand. Since you can only have one grouping column, i am stuck. i am thinking a concatenation field may help but the text format causes other sorting issues. for example it shows 1-2018, then 1-2019, 10-2018, 11-2018, as opposed to a monthly order.