FARR WEST -- Opening his mission call will be just a little more exciting next week for 18-year-old Trevor William Thompson.
That's because Thompson is well-aware that he's about to become part of the greatest missionary force The Church of Jesus Christ of Latter-day Saints has ever known.
The number of Mormon missionaries surpassed 75,000 worldwide in August, driven by the church's decision to lower the minimum age for ambassadors of the Utah-based faith, the church has announced. Officials expect the number to swell to 85,000 by year's end.
The church said the number of proselytizing missionaries already has increased by 28 percent from about 58,000 a year ago.
"I know the work is being done," Thompson said. "With so many people out there, it will definitely help out."
The recent Fremont High School graduate said he has been told his entire life that missionaries eventually would reach all the corners of the world.
"With 85,000, I'm pretty sure we can cover the entire world," he said. "It helps to know that every part of the world is being preached to."
Last October, the church announced men could begin serving at age 18, instead of 19, and women at 19, instead of 21.
Church leaders and outside scholars expect the decision will lead to many more women serving missions.
Rather than having to leave at age 21 -- when many women are about to start careers or perhaps are contemplating marriage and starting families -- Mormon women can now serve missions shortly after high school.
Kelly Shepherd, the director of the Ogden LDS Institute, said enrollments there are expected to be affected by the higher volumes of young people serving missions.
He and his staff are applying increasing strategies to attract more students as a result.
"We know Weber State University is experiencing a 6 percent decrease from last year in preliminary enrollment," he said. "They can't tell how much that is due to missionaries."
Shepherd said officials expect enrollment at the Institute to be affected. When two instructors retired last year, only one was replaced, bringing the number of full-time instructors this year to 14.
However, he said promotional efforts should increase enrollment to make up for the losses.
"We will pick up, not drop, because we are going to create enthusiasm," he said.
But he knows for sure that fewer 18-year-olds will be at the Institute this year regardless.
"We've seen pictures in seminaries with kids with their mission calls," he said.
Young Mormon men are expected, but not required, to serve missions. Historically, women have faced far less pressure to serve, according to reports. Men serve two years, while women go for 18 months.
Church scholars say the unprecedented number of missionaries gives Mormons an opportunity to bring in a higher number of converts, and perhaps more importantly, do a better job of keeping current members active.
The church reported having 14.4 million members worldwide as of January 2012.
Missionaries convert about five people per mission, according to Matt Martinich, a member of the LDS Church, who analyzes membership and missionary numbers with the nonprofit Cumorah Foundation.
The Associated Press contributed to this report.