It depends which kind of report are you seeking for, basic daily and weekly graph are configurable on the MK itself (see http://wiki.mikrotik.com/wiki/Manual:Tools/Graphing#Interface_graphing), if you need something more then you need a tool which is able to send SNMP requests and do your magic on that device.
Just a small side note: if you use embedded graphing do not write on NAND device but keep them on RAM on on external USB drive.