Unique Visitors metric in Google Analytics

Hi All,

I am using Google Analytics Source in SSIS. Here is the link of the API I am using:

http://www.google.com/analytics/apps/about?app_id=1325007

My question is that how would I calculate "Unique Visitor" metric in GA or what is the exact name of  this metric in GA source ?

Please let me know if I am using the correct API or not?

Thanks,

NSM