Calculating Adjusted Basis for personal use property

Hi,

 

I purchased a personal use property in a foreign country. The agreement was signed in 2011, when the construction started. The payments were made every year until 2016 and then I got the possession. Will the Cost Indexation/Adjusted Basis be calculated based on 2011, when the contract was signed? Or will it be calculated separately for each year from 2011-2016 based on the payments made for that year?

 

Thanks.