If you are subscribed to the Webcast Metrics reports you can get weekly reports for TLH, Cume, AQH, TSL, Started Session, Active Sessions, Average Active Sessions and Peak Sessions from Webcast metrics reports screen.

To access them just click the Webcast Metrics link at the top of the screen, then click the Webcast Metrics start link.  That will load the default daily report for the past two weeks.  To run a weekly breakout report, just set your start date and end date, then change the interval to Weekly and click Generate.

Then you'll get a week by week listing for each full week that have reported stats for during your requested date range.

Keep in mind though that these reports are four days behind so last week is the most current full week you will be able to get.  This week’s report will be ready next Friday