Date Range Comparison report

Hi

Is it possible to create a report on "Leads Created" that compares 3 date ranges, particulary by specific weeks? 

For example: look at last 7 days leads created versus the 7 days before that versus the 7 days before

that?

I have tried a Summation Report with three Filter Groups of

OR

Date created Is Between 01/04/2016 AND 07/04/2016

Date Created Is Between 08/04/2016 AND 15/04/2016

Date Created Is Between 16/04/2016 AND 23/04/2016

I've defined

- "Define Group By"   =  "Date Created"

- "Display Summaries" =  "Date Created" and "Count"

Chart Type is Horzontal Bar

Result is that the leads get grouped on chart by individual Day and not date range

Is there any way to do that?

Thanks