Year-to-year membership statistics for the LDS Church place the Utah-based faith among the fastest-growing religious traditions in the U.S. and Canada.

Comparative statistics from the 2009 Yearbook of American and Canadian Churches, which was released in February and uses church data from 2007, show that among the 25 largest faith traditions in the U.S., the LDS Church was one of four to chart membership increases over 2006 numbers.

According to the data, membership in The Church of Jesus Christ of Latter-day Saints grew by 1.6 percent from 2006 to 2007. At the same time, membership in both the Jehovah's Witnesses and the Church of God of Cleveland, Tenn., grew 2 percent. The Assemblies of God grew by 1 percent.

The yearbook is published by the National Council of Churches and uses figures provided by different faiths.

Comparing growth rates among faith traditions can be like comparing "apples to hubcaps," because churches vary in their methods for counting members, said Eileen Lindner, editor of the annual yearbook, which has compiled data on church membership, giving and personnel for more than 75 years.

Some churches record membership upon a person's baptism as an infant and never alter the record, even if the person discontinues religious practice. Other faiths count only adult members who meet detailed, vigorous attendance and financial contribution standards.

The value of the data is really in showing the year-to-year growth patterns within individual churches, Lindner said. LDS Church data is considered highly reliable because the church employs professional demographers to track the numbers, she said.

Data released Saturday by the church placed its worldwide membership at 13.5 million as of Dec. 31, 2008. That's up from 13.1 million in 2007, and 12.8 million in 2006.

The data show more than half of the growth — 265,593 — were converts drawn to the faith by its missionary force of about 52,000. The balance came from other baptisms and children born into the church.

"The more the better," said Elder Bruce D. Porter. "But growth is not our main focus."

Still, Mormons believe they are called to share the word of God and the message of what they consider a "restored Gospel" on Earth.

The church is known for its proselytizing missionaries around the world. About 75 percent of church missionaries are men under age 26. Roughly 18 percent are women and about 7 percent are older couples.

The LDS Church began in 1830 with just six members, primarily its founder Joseph Smith Jr. and his family. The church has never had a negative growth year, Porter said.

"However, when we think of growth we don't think only of numbers and statistics," he said. "We think also of the spiritual growth of our members."

Mormon membership is primarily based on the number of individuals recorded after baptism, Porter said. Annual membership counts also reflect the number of children born to members, but drops the youngsters from the roll if no baptism occurs by age 9.

Names are also removed from the rolls if a member is excommunicated, voluntarily elects to resign from the church or when the church receives confirmation of a death, Porter said.

The church doesn't make projections about membership growth, nor does it compare its numbers to those of other faiths, he said.

Numbers provided to The Associated Press by the church last week show that in 2007, 54 percent of Mormons lived outside of North America.

The data show that over a 10-year period beginning in 1997, the church grew by 19 percent in the U.S. and Canada, adding roughly 77,500 members. At the same time, some 2.1 million people joined the church outside North America, an increase of 43 percent. Membership rose by 142 percent in Africa and by 50 percent in Asia. The growth rate in Europe was the slowest at 17 percent.