The report indicates that as of March 31, 2013, USCIS has received a total of 488,782. Of which 472,004 has been accepted for processing, and only 268,361 has been approved. It also shows Mexico, El Salvador & Honduras as the top 3 countries of origin, while California, Texas & New York are the top 3 places of residence.
"Please also note that the Deferred Action for Childhood Arrivals reporting period will change from a mid-month to an end-of-month cycle. In addition, beginning with the April 2013 report, the reports will include updates to data previously reported based on the availability of data as the Deferred Action for Childhood Arrivals process progresses."
The report is available here: