USCIS recently updated PERM statistics as of 06/30/13. This statistics will also give you an idea of current level of demand in various EB categories. Demand is currently 4% higher than last year.
In the last nine months around 28,000 PERM applications (out of 54,000 received) have been approved. 83% of total approved applications are filed by H1B visa holders. 59% of approved PERM applications are filed by people from India.
The next highest is from China at only 7% and Canada at 5%. The gap between India and China VB date (in EB2 and EB3) will continue to increase. MS/PhD holders are at 53% compared to BS degree holders at 38%. Please see more details below: