Did you present the exact same question to the folks at Zillow?
My continuous study, covering the sale of 100's of home in 8 pricing brackets reveal ZILLOW is the purveyor of egregiously incorrect data.
The CEO of Zillow, in a conversation regarding Zillow's acquisition of TRULIA stated, 'zilow and trulia are both ADVERTISING websites, not real estate websites, therefore not under the control of the Securities and Exchange Commission.
In essence the data found here or on Zillow is no more reliable than getting life advise from the Big Bang Theory or your news from the Daily Show. You do not get your life advise or news from those shows...right?
The great public deception under which you have fallen should stir a great fear within us all. That fear must be the centralization of information. Those who control the information....CONTROL OUR LIVES. This has worked well for China and North Korea and Russia. When only one source exist for real estate information, ........ I hope you see the DANGER.