By JACK GILLUM and TED BRIDISWASHINGTON (AP) â¿¿ The U.S. government, led by the Pentagon and CIA, censored or withheld for reasons of national security the files that the public requested last year under the Freedom of Information Act more often than at any time since President Barack Obama took office, according to a new analysis by The Associated Press. Overall, the Obama administration last year answered its highest number of requests so far for copies of government documents, emails, photographs and more, and it slightly reduced its backlog of requests from previous years. But it more often cited legal provisions allowing the government to keep records or parts of its records secret, especially a rule intended to protect national security. The AP's analysis showed the government released all or portions of the information that citizens, journalists, businesses and others sought at about the same rate as the previous three years. It turned over all or parts of the records in about 65 percent of requests. It fully rejected more than one-third of requests, a slight increase over 2011, including cases when it couldn't find records, a person refused to pay for copies or the request was determined to be improper. The government's responsiveness under the FOIA is widely viewed as a barometer of the federal offices' transparency. Under the law, citizens and foreigners can compel the government to turn over copies of federal records for zero or little cost. Anyone who seeks information through the law is generally supposed to get it unless disclosure would hurt national security, violate personal privacy or expose business secrets or confidential decision-making in certain areas. The AP's review comes at the start of the second term for Obama, who promised during his first week in office that the nation's signature open-records law would be "administered with a clear presumption: In the face of doubt, openness prevails." The review examined figures from the largest federal departments and agencies. Sunday was the start of Sunshine Week, when news organizations promote open government and freedom of information.