"Amount of Depreciation Taken in Prior Years" on an foreign rental property?

Hi, I'm filling out my first full US tax return.

I have a rental property which has been making income since 2012 in the UK. 2016 is the first year I will have to pay US taxes on this income having moved here at the end of 2015.

As i have never filed US taxes for the rental income and depreciation what do i put in the box for the question "Amount of Depreciation Taken in Prior Years"? Having never filed a tax return or taken any depreciation amount do i just put $0?

The Turbotax software inserted a figure based on the information i gave regarding the cost and active date of the rental property.

Any help would be grateful! Thanks