Perhaps I'm misunderstading the numbers here, but it looks like for example, the Mon, 02 July 2012 12:07:22  had an incremental increase in size of 1.8 MB. But there was no changes made to the server and no usage activity that would explain such a large increase. And this seems to be happening pretty much every day.

Can you please explain what's happening?

1.8 MB (inc)

Restore

Mon, 02 July 2012 12:07:22 UTC