The federal government cut the number of individuals holding security clearances by a quarter of a million people in fiscal 2015, according to a new report, marking the second consecutive year agencies have successfully followed through on an Obama administration goal to trim the cleared population.

The Office of the Director of National Intelligence report showed agencies continuing to reduce what had been a growing population of federal employees and contractors who hold clearances. The number of people with clearances had ticked up in each of the first three years since ODNI began measuring it in 2011.

The total reduction in 2015 continued a multi-year trend of federal agencies doling out fewer new security clearances each year.

About 4.2 million individuals held security clearances as of Oct. 1, 2015, down 6 percent from the same time in 2014. The cleared population has fallen by about 17 percent since fiscal 2013. The new approvals for security clearances -- including first-time issuances as well as reinvestigations -- dropped 4 percent to 639,000.

The ODNI said the decreases stemmed from the Defense Department ensuring better data quality, as well as “the result of efforts across the [U.S. government] to review and validate whether an employee or contractor still requires access to classified information.”

About one-third of the total cleared population was not considered to be eligible for sensitive information but did not have access to it at the time of the report. Federal agencies cut the number of “not in access” cleared individuals by 13 percent from 2014.

The Obama administration vowed to reduce the number of cleared individuals by 10 percent by 2018 compared to five years prior. Defense has issued several directives to identify employees who no longer require clearances and strip them of the status, and has shed 17 percent of its security clearance holders since 2013.

In the three years since former National Security Agency contractor Edward Snowden leaked hundreds of thousands of classified documents to the press and contractor Aaron Alexis fatally shot 12 people at the Washington Navy Yard, the White House and lawmakers have proposed myriad changes to the security clearance process. Reform efforts have focused on reducing the amount of classified information as well as boosting reinvestigation efforts.

Most recently, the Office of Personnel Management announced it would create a new entity -- the National Background Investigations Bureau -- to oversee the security clearance process. OPM is currently standing up NBIB, though lawmakers have repeatedly questioned the new component.

Losing a clearance after initial approval remains a rare occurrence. The National Security Agency rejected recertification more than any intelligence agency, according to the report, stripping just 2.3 percent of clearances, followed by the FBI at 2 percent. The State Department approved 99.9 percent of both its reinvestigations and initial cases.

The CIA rejected the highest rate of initial clearance applicants, denying 8.5 percent.

The intelligence community specifically, the ODNI said in the report, has struggled with the “competing requirements” to reduce the reinvestigations backlog while meeting timeliness goals for initial security clearance processing. It is also struggling to keep pace for applicants with unique skills, such as those with fluency in foreign languages who have had “significant foreign associations” that must be investigated. Investigations fell further behind last year when OPM temporarily shut down the e-QIP system.