I would like data on what median rents have historically been in
Massachusetts.  This data should at least be annual.  Ideally, it
would cover at least 1968 - 2005 inclusive, although 1985 - 2005 would
also be acceptable.  The data should be publicly available, preferably
from a government agency, although other reputable sources would also
be acceptable.

Tips will be provided for the following optional things:

 - Data which is likely to be added to in the future (e.g., 2006).

 - Data which is released more frequently than annually.

 - Data which is provided in separate sets by household size.