I just set up an ArangoDB instance (2.8.7) on a t2.medium machine at AWS Cloud with Ubuntu Server (Ubuntu Server 14.04.03 and 14.04.04 LTS (HVM), SSD Volume Type - ami-87564feb) and followed all of the mentioned tutorial steps (https://www.digitalocean.com/community/tutorials/how-to-install-and-use-arangodb-on-ubuntu-14-04). Unfortunately I cannot reproduce your described behaviour.
Could you please verify that statistics are not disabled?
Default-Config-Path: /etc/arangodb/arangod.conf
Please add this setting under server (if not present):
[server]
disable-statistics false
Also it could be helpful if you could open the developer console of your browser and post the output here.