Unintentional landlord... do I depreciate?

[Na Na]

Hoping from some help from this excellent BP community, since I am doing my own tax return. It is usually very simple for me.

I purchased my condo in 2006. Permanent residence until military transfer in 2010. I have rented the property since 2011, but have never deducted property deprecation on my tax return. Should I?

If so, how do I calculate the property depreciation for 2013? The purchase price in 2006 with in-service date of 2011? Purchase price in 2011 with in-service date of 2011?

I plan to sell the property when the market returns, hence the "unintentional landlord."

I do not have any other investments (properties).

Please PM if you wish to take this offline.

Thank you.