[tor-relays] Mystery of bridge utilization

I've got 2 bridges, with 1 IP address in each of 2 servers in the same geographical area. The IP addresses are not consecutive. Both servers have the same hardware and software configurations. Both were established in mid-January and (excepting a few brief periods of down time) have been running since then. So why then in March did one server handle 200GB of traffic while the other handled only 2GB? (Yes, a x100 difference.) Also: is there something I can do to make my under-utilized bridge more attractive to the Bridge Authorities? Thanks.