Project size shows weird values

Yesterday, the projejt size of the https://gitlab.com/gitlab-org repository reported a size of 1.2 GB, which is a value I don't trust.

Screenshot_from_2016-07-13_19-05-28

Today the project size shows a size of 1.7 GB.

Screenshot_from_2016-07-14_08-28-02

Something strange is going on here. Normally, I would assume a size of about 300 MB.

/cc @rspeicher @connorshea