Kay Lotulelei says when she drops off some of her nine children at Brighton High School or the private Waterford School, others often "are open-mouthed. They think, 'That's quite a lot.' Most of their families average only one or two kids."

Of course, Utah is well-known for having lots of babies and big families. And those like the Lotuleleis — or even families with "merely" four or five children — have helped Utah again reach statistical heights that no other state comes near in a new census survey released today.

It shows Utah has the nation's largest household size; both its men and women marry at the youngest ages in America; a higher ratio of its women give birth each year than in any other state; more of its households include children; more households are led by a married couple; and more of its children have at least one stay-at-home parent.

The Lotuleleis of Midvale give faces to such numbers. Their household has 11 people. Husband Tevita was 25 when they married, and wife Kay was 23, about average for Utah, but young for most Americans. Their five girls and four boys range in age from 17 to 4. Kay is a stay-at-home mom.

"Actually, I'm more of a stay-in-the-car mom," because she drives her children to so many activities, Kay says.

"Utah is indeed different," said University of Utah research economist Pam Perlich, noting that the state often ranks at the extreme of ranges in categories that measure family characteristics in the 2007 American Community Survey, an annual survey of millions of Americans by the Census Bureau.

Some such categories include:

• Biggest average household size, 3.11 people in Utah (19 percent larger than average).

• Youngest age at first marriage both for men (25.2) and women (22.8). The national average is 27.7 for men and 26 for women.

• Highest ratio of women giving birth in the past year (7.9 births per 100 women ages 15 to 50). That is 44 percent higher than the national average of 5.5.

• Lowest percentage of children under age 6 with all parents in the work force, 50.3 percent. The national average is 61.7 percent.

• Highest percentage of households that are married-couple families, 62.3 percent. That is 25 percent higher than the national average of 49.7 percent.

• Highest percentage of households that are married-couple families that have children under 18 years old, 32.4 percent (compared to a national average of 21.4 percent).

• Percent of households with one or more person under age 18, 43.1 percent (or 25 percent higher than average).

Perlich said, "It is quite clear there is a cultural component driving the higher fertility rate" in Utah, namely its high percentage of residents who belong to The Church of Jesus Christ of Latter-day Saints, which puts strong emphasis on families.