EB2 NIW (NYC) Processing Time.

Hi, living in NYC. About to file I-140 and I-485 concurrently for EB2 NIW Green Card. Visa Bulletin current for me. Have read on internet that processing times for I-140 and I-485 posted on USCIS website for Texas Service center is "National Average" processing time. Am a little confused. What does that mean? And though I understand my lawyer cannot (and should not) guarantee anything, is a timeframe of 12 months from filing date to receipt of Green Card realistic? Assuming its an approvable case, no RFE, no security check issues, etc. Thanks. - Is this your question? Add additional information