Email Performance Report

With the Email Performance Report I can look at specific emails sent over a certain time period. However, I'd like to see and compare email performance over different time periods within the same report. For example, I can see email performance for January, but if I want a single report that shows how those emails performed the 1st week of January, compared to the 2nd week of January compared, to the 3rd week, and so on, I have to run individual reports for each week and combine them in Excel, which is time consuming. Anyone know an easy way to get the report I need? If I can't do this in Marketo does anyone know of a third-party option that could generate this type of report? Thanks.