Confused on the China EB3 data.

This file shows the demand prior to 01/01/2006 is 4,625 (at the bottom of the file, it shows as of year 2010 - do not know if that is a typo). In another file which shmu posted (a few posts below) with this link: http://www.uscis.gov/statistics/Employment%20Based%20I-485%20Pe shows 2,348 after adding all prior to 2006. Where the difference comes from?