I485 for VSC or NSC?

I filed I140 (NIW) to NSC March 2003 when I was a graduate student in Michigan. But I moved to Boston as a postdoc Oct 2004. I just got I140 (NIW)approved recently from NSC. However now I am working and living in the area of Vermont center.
My question is: should I file I485 to NSC or VSC?
Thank you for your answer!