The Central Government has announced 7% additional DA for Central Government employees with effect from January 2012. Now the total DA will be 65%, increased from 58%. The total expenditure because of the additional DA is expected to be around Rs. 7500 crore.
Central Government employees’ DA are revised twice in the year, in January and July, while BSNL employees /PSUs get every three months, in January, April, July and September.
VAN Namboodiri's Blog 
TOTAL CDA 65%. THIS IS FOR A TOTAL OF 6 YEARS. i.e. 2006,2007,2008,2009,2010&2011. THAT MEANS 65/6= APPROX. 10.8% PER YEAR ON AN AVERAGE.
TOTAL IDA 56.7%. THIS IS FOR A TOTAL OF 5 YEARS. i.e. 2007,2008,2009,2010&2011. THAT MEANS 56.7/5= APPROX. 11.3% PER YEAR ON AN AVERAGE.
COMPARATIVELY CPSU EMPLOYEES ARE BETTER PLACED AS FAR AS DA IS CONCERNED COMPARED TO CG EMPLOYEES.
BHASKAR
MYSORE