The annual report, released Thursday, representing the classification and declassification activity throughout the executive branch, said the cost of national security classifications totaled $9.91 billion in 2007. The total cost was a 4.6 percent increase over 2006 and became the highest total recorded in ISOO's history.

ISOO's security classification costs include physical security and computer security, among other needs for information security, the Federation of American Scientists reported.

Officials say 37.2 million pages were declassified from the U.S. government out of 59.7 million pages that were requested for review. The figures recorded represent a decrease in the number of pages that were reviewed in 2007 and also a decrease in the total number declassified.

But ISOO reported an increase in the rate of declassification and a 1 percent increase in the overall number of security classifications.