Cacti - http://www.cacti.net/

Exported Graphs

Graph - Richmond WiFi - Clients
Hourly (1 Minute Average)

Daily (5 Minute Average)

Daily (5 minute snapshot)

Weekly (30 minute snapshot)

Weekly (30 Minute Average)

Monthly (2 Hour Average)

Monthly (2 hour snapshot)

Yearly (1 day snapshot)

Yearly (1 Day Average)