Board Thread:Speculation House/@comment-82.12.156.248-20140310081810/@comment-10380701-20140310092754

Probably an assumption. I just did a search on the wikia and there's no info of the Black Trailer taking place a year before Volume 1. Of course, given Blake's appearance in the Black Trailer, it's simple to assume that it's only been a year or so, since she doesn't look that much different.