The graphic depicts pricing of all homes from their ‘peak through current declines’ as per Case Shiller. This index looks at prices in 20 major metropolitan areas.

Each market peaked at different times. Therefore, the InfoGraphic doesn’t cover one segment of time. Here is a site where you can see when each market actually peaked:

http://www.housingviews.com/2011/11/29/how-the-cities-did-in-the-latest-release/how-cities-did-september-2011/