Whether or not you are able to locate those answers, I would be confident to say that the averages will certainly change due to the very different nature of the housing economy. In other words, the trends that led into 2006 and the height of the market will certainly be tempered by all that has happened since.
Sorry I cannot offer better insight.
So you can see that, like most aspects of real estate (& finance), there are a lot of variables.
Hope this is somewhat helpful.