Concurrent Sessions

I am trying to get the Max Concurrent Access Sessions (over a period of time) as is displayed in the BIG-IQ GUI, but through the API. I have located the Device Traffic metric set in the Analytics endpoint and, particularly, the server-concurrent-connections Metric. However, this is concurrent Connections, not concurrent Sessions. Does anyone know where concurrent access sessions information would be located as I have scoured the documentation to no avail.