Border Patrol agents apprehended a smaller share of border crossers here and across the Southwest in fiscal 2013 than in the previous year, as more of them turned back to Mexico or got away, the agency’s data show.

The increase was particularly stark in the number of “got aways,” crossers who were spotted but not caught. The size of that group jumped 68 percent, from 22,000 to 37,000, in the Tucson Sector. A similar increase was seen across the Southwest, according to data obtained through a Freedom of Information Act request. The federal government took a year to respond to the Star’s request for information.

Apprehensions from 2012 to 2013 rose less than 1 percent in the Tucson Sector and 16 percent in all nine sectors of the Southwest.

There are limitations to the data, including inconsistencies as to how each sector records those who got away and those who turned back and the possibility of someone being counted more than once. But it’s the current way that the agency measures border security, together with number of apprehensions.

Agency officials, who did not respond to repeated requests for comment, have said the numbers are reliable enough to assess each sector’s progress and to help determine resource deployment.

In September 2012, the Border Patrol advised sectors to “provide a more consistent, standardized approach for the collection and reporting of turn-back and got-away data,” a 2013 Government Accountability Office study says.

For U.S. Rep. Ron Barber, a Democrat from Arizona, the biggest problem is that the Department of Homeland Security has not implemented a new system to adequately measure border security more than a year after the agency said it would have something in place.

In 2011, the DHS started to track border activity using apprehensions — not the number of people caught at the border, but the number of times it caught a border crosser, meaning one person can be counted multiple times. At the time it cited a need for new goals and measures for border control. But last February, the Government Accountability Office said the Border Patrol still didn’t have goals and measures in place to inform about the status of border security — and that remains true today, Barber said.

“I’ve gotten promises that they are working on it,” Barber said. In December, Jeh Johnson was sworn in as the new DHS secretary, and Barber said he has received assurances that Johnson will get the job done.

Barber has pushed for legislation that would require the agency take into account information from border stakeholders, including ranchers, town residents and Border Patrol agents. Until then, he said, the numbers will not be credible.

Of the total number of what the agency refers to as known illegal entries — meaning people identified by the Border Patrol either through cameras, people in the community, other law-enforcement officers or footprints — the agency caught about 56 percent across the Southwest border in 2013, down from 61 percent in 2012.

Those percentages were lower in places such as Texas’ Rio Grande Valley, where traffic has increased the most. Fewer than half of those detected were caught there.

Art del Cueto, president of the local Border Patrol union, said he blames the higher number of people who got away to funding cuts, including those from sequestration, which have reduced the time agents are out in the field.

Whether or not the numbers are reliable, del Cueto said, for now they’re the only ones that exist.

“You could always find a flaw in any method,” he said, “but that’s what we have to work with.”

The National Border Patrol Council is pushing for a pay reform that del Cueto said would increase the number of hours an agent is in the field. On Thursday, the Senate passed the Border Patrol Agent Pay Reform Act of 2013. It awaits further action in the House.

Visit tucson.com to see the numbers for all Southwest Border Patrol sectors.

Contact Star reporter Perla Trevizo at 573-4213 or ptrevizo@tucson.com. On Twitter: Perla_Trevizo.