My 485 processing time is taking too long for ROW

[sark33]

My I 140 was approved under EB2-NIW in Jan , 2013. My I-485 was received by TSC on March 20, 2013 and my biometrics was taken on April 24, 2013. It's been more than 4.5 month after my 485 application, still I am waiting for my Green Card. I checked the processing time for ROW in Texas Service Center, which was 4 month (current). I called USCIS to check my application in August 5, 2013 and they said that TSC was processing application for February 1, 2013. Can anyone predict how long it might take to get my Green Card?
Thank you.