check_local_mrtgtraf returns wrong values


i have nagios checking bandwidth on a port 1 of a router and it is giving me different values. the mrtg graph is correct

here is my info:

define service{

use			generic-service	; Inherit values from a template

host_name			corerouter

service_description	Port 1 Bandwidth Usage

check_command		check_local_mrtgtraf!/var/lib/mrtg/r1.log!AVG!1000000,2000000!5000000,5000000!10