If you're just eyeballing it, the RF Capacity page is pretty useful, but it is limited to a 24 hr view.
You're best bet would be to run a Client Session report, and make sure to include connection mode list and details, and then details for all sessions. This way you can sort by connection mode.
For the 1 month part, you need to make sure that you're maintaining a months worth of data, otherwise it will only provide data points for the data that exists in the database. Check AMP Setup -> General -> Historical Data Retention values for Client Associations and Inactive Clients. These 2 settings determine how long client data is maintained in the database.