Craig Healthy, Homeland’s assistant director for national security investigations, admitted that there are just 3,000 active investigations, or .05 percent, into some six million aliens who have illegally overstayed their visas in the United States during the past 20 years.

Investigators have additionally “exhausted” 1,626 “leads” into these individuals, Healy disclosed under questioned by Sen. David Perdue (R., Ga.), a member of the Senate Immigration Subcommittee.

Healy’s disclosure comes on the heels of a report by DHS revealing that more than half a million aliens overstayed their temporary visas in the United States in 2015 alone and ore than 482,000 of those individuals are believed to still be residing illegally in the United States, according to the report.

This includes 219 illegal overstays from Afghanistan, 681 from Iraq, 564 from Iran, 56 from Libya, 1,435 from Pakistan, 440 from Syria, and 219 from Yemen, according to the report. Many are still in the United States illegally.