Stats menu unites cloud usage and CDN usage statistics generated by the OnApp Statistics receiver.
The statistics receiver is an SNMP agent that collects data from host and guest systems and saves it in the round-robin database for the future processing. The collected data are then converted into hourly, daily, weekly and monthly statistics. The interval can be changed in the application configuration file.
Hourly statistics are stored in the database for the last 2 months.
Daily statistics are stored for 12 months.
Old statistics data are stored as a monthly statistics (12 months, respectively).

The Usage Statistics screen lists every virtual machine in the cloud, along with their details:

By default, statistics are generated for the last 72 hours. To specify another period, set the Start and End time and click the Apply button.
You can sort by all categories except the virtual sever name: click a column label to sort in ascending order (you'll see an arrow appear to show how the data is being sorted). Click it again to sort in descending order.
You can also drill into a specific VS, or its owner, by clicking the relevant links in the list.