Nearly 250,000 undocumented immigrants applied for U.S. citizenship in the four-month span beginning October 2015, according to a Pew Research Center analysis.

Preliminary data released by U.S. Citizenship and Immigration Services (USCIS) found 249,609 legal permanent residents completed N-400 forms this fiscal year, a five-percent increase from the same period heading into the 2012 presidential election. It also marks a 13-percent jump from October 2014 to January 2015.

Pew researcher Jens Manuel Krogstad acknowledges the effect Republican presidential front-runner Donald Trump has on undocumented individuals -- namely his way of stoking anti-immigration rhetoric -- but the influx of applicants may not be related to Trump at all.

Previous years have seen bigger spikes. In 2007, USCIS received over 1.4 million applications after the Department of Homeland Security announced a $265-fee increase. Stringent immigration laws led to the second-largest increase -- 900,000 people between 1995 and 1998 -- after Congress limited public benefits non-citizens could receive.

"Though not yet available, it's possible the data will show the number of naturalization applications increased this spring -- number have spiked in March and April in past years," Krogstad said. "Applications may also continue to rise into the summer, though how many of these new applicants will become naturalized in time to register to vote remains to be seen."

The process of attaining U.S. citizenship takes years; successfully submitting an application takes six to seven months on its own. Unless they marry a U.S. citizen, legal residents must have lived in the country five years to become eligible.

Citizenship Fee Changes

On May 4, DHS released an updated USCIS fee schedule adding 21 percent to the $595 applicants already pay, as well as an undescribed new fee.

One reason, as the DHS letter noted, is that "currents fees do not recover the full costs of the services it provides." USCIS anticipates shortcoming of $560 million without the increase; an allocation of funds which would go to the Systematic Alien Verification for Entitlements Program (SAVE), the government-funded programs that determines if immigrants are eligible for benefits.

DHS proposed a three-level fee system for new applicants. The first covers the N-400 form cost -- from $595 to $640 -- and the second grants waivers for military personnel.

In an effort to aid immigrant families, DHS also proposed reduced fees for applicants with family incomes greater between 150 and 200 percent of Federal Poverty Guidelines. They hope the change will "increase access to United States citizenship."

Advocacy Group Drawing More Applicants

The Pew Research Center analysis does not draw a correlation between Trump and incoming applicants, but months-longs efforts from labor unions, non-profits, and immigration advocacy groups indicate the GOP candidate is having an immeasurable effect on immigrant communities.

The Obama administration has distributed $10 million in grants to encourage eligible non-citizens to apply for citizenship. In March, the collaborative "Stand Up to Hate" campaign aided some 12,781 individuals fill out applications.

"Stand Up to Hate" -- composed of Mi Familia Vota, UFCW, and the Latino Victory Foundation, among other groups - has spent the better part of the elections cycle educating undocumented immigrants about their rights, and of a possible pathway to citizenship.