Slow internet

Have the premier package but have been getting down into the 29-30 Mbps down and 5 Mbps up range lately. That is just a little over half the speed I am supposed to be getting and these numbers were taken late at night off of peak hours. It frequently will stall out when trying to view videos from various sources and have to wait for it to "buffer" for a while. My modem is a few years old, don't know if a new one would help or not, but seen some people getting help on here so I figured I would try.

Start Cox Net Download Speed Upload Speed Latency Your IP Address Cox Market Thu Jan 23 01:32 AM Yes 28 Mbps 5 Mbps 15 millisec XXXXXXX Oklahoma City Thu Jan 23 01:31 AM Yes 30 Mbps 5 Mbps 15 millisec XXXXXXX Oklahoma City Wed Jan 15 04:15 AM Yes 28 Mbps 5 Mbps 21 millisec XXXXXXX Oklahoma City Wed Jan 15 02:45 AM Yes 29 Mbps 5 Mbps 19 millisec XXXXXXX Oklahoma City