I took a packet capture and noticed it's sending this about 20 times per second:
[ void Galaxy::update(float): 8.061 ms; 15.8% ]
[ void Galaxy::updateSectors(float): 7.391 ms; 14.5% ]
[ void Galaxy::updateJumpingEntities(): 0.615 ms; 1.2% ]
[ void Galaxy::updateWormHoleResults(): 0.015 ms; 0% ]
[ void Galaxy::updateEntityTransfers(): 0.003 ms; 0% ]
[ void Galaxy::handleFinishedScriptPacketCallbacks(): 0.001 ms; 0% ]
[ void Server::updateDebugDiagnostics(): 1.182 ms; 2.3% ]
[ MessageServer update: 0.387 ms; 0.8% ]
[ virtual void SteamNetworkingServer::update(): 0.374 ms; 0.7% ]
[ void SteamNetworkingServer::sendUpdatedServerDetailsToSteam(): 0.349 ms; 0.7% ]
[ void SteamNetworkingServer::processReceivedNetworkData(): 0.007 ms; 0% ]
[ Steam Callbacks: 0.006 ms; 0% ]
[ void SteamNetworkingServer::updatePendingClosing(): 0.005 ms; 0% ]
[ void SteamNetworkingServer::updateTimeouts(): 0.001 ms; 0% ]
[ void Server::updatePlayerCommunicatorAdministration(float): 0.276 ms; 0.5% ]
[ Send Regular Server Info: 0.054 ms; 0.1% ]
....Sectors Updated: ....19....avg. server load: ....19.4%
...avg. update: ....10 ms
...max. update: ....14 ms
...min. update: ....5 msd...
Does the client actually do anything with this data? If not it's probably a good idea to omit it as it's between 10 and 20% of the current bandwidth just to send that text at that frequency.