This is what I got by comparing INS stats for March 2003 vs March 2002
App Year Pending Rcvd Pending Prcssd
Type from Feb in Mar End Mar
=====================================
I765 2003 400632 148263 396571 152324
I765 2002 213769 143488 224938 132279
=====================================
I485 2003 1094920 60334 1118087 37167
I485 2002 888264 143488 858941 172811
So "LOW PRIORITY" means processing at about 1/5 th speed.

App Year Pending Rcvd Pending Prcssd
Type from Feb in Mar End Mar
=====================================
I765 2003 400632 148263 396571 152324
I765 2002 213769 143488 224938 132279
=====================================
I485 2003 1094920 60334 1118087 37167
I485 2002 888264 143488 858941 172811
So "LOW PRIORITY" means processing at about 1/5 th speed.