http://dolstats.com/info/a_number

Each number consists of the letter "A" and two groups of digits. For example #A-12001-XXXXXX. "A" means that it's a perm application case. Five digital part consists of a two-digit number for the year of the application coming first (12 stands for 2012), followed by a three-digit number meaning the exact day of the year. For example 001 stands for the January 1st, 058 - February 27th and so on, finishing with 366 for December 31st for a leap year. This is the date when the draft was created in the system (but not the date when the application was sent). "XXXXXX" is a unique digital combination for each of this days (this information is not proved by any facts, it's not known if this part of the number means anything specific).

It is possible to tell which group of cases is considered by the DOL at a given moment of time based on the analysis of the cases already reviewed. So if a group of cases with number «A-13100-XXXXXX» was examined during the last week and yours is «A-13101-XXXXXX» you may hope to get the DOL decision soon. But there are no guarantees, cause your case can be set aside for a while or, on the contrary, be reviewed ahead of your “group” with no obvious reason.