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 Average)

Weekly (30 minute snapshot)

Monthly (2 Hour Average)

Monthly (2 hour snapshot)

Yearly (1 Day Average)

Yearly (1 day snapshot)