Yvonne,
Refine your current report say for example Project Cost and Revenue by Project Report, click on the report. Fill in all the other fields, on the accounting period/year--> click on it go to basic select and click on advanced--> between --> last invoiced month to current last month you want--> click on ok. Then run your report as normal and select from not currently shown what you want to display.
You can also add field by going to the top screen and clicking on add fields, then tick the fields you want to display on the report.
Hope this will help you
Regards,
Emeka