People just keep moving to Snohomish County, which has supplanted King County as the Puget Sound region's fastest-growing area.

With them come the numbers that reveal bits and pieces about them, from county- and city-council meetings, from planning-commission and growth-management meetings. Pie charts, bar charts, tabular charts break down the demographic information in many ways.

They all show that Snohomish County is filling up fast.

Based on projections done under the state Growth Management Act, the county is expected to have nearly 900,000 residents by 2025. There were 465,642 people in the county in 1990, and the most recent estimate, for 2003, was that 637,500 people lived here.

But the numbers don't tell everything.

Why do people move to Snohomish County?

A chart prepared for one study, the Snohomish County Tomorrow 2003 Growth Monitoring Report, indicates county growth is tied to economic conditions.

In bad years, the population went up, at least a little. In good years, it went up considerably more.

During a boom in 1978-79, for example, there was a 20,000-resident jump. In the good times of 1988-89, the population went up 22,000. And in the rich years of 1997-98, when the region was awash in airplane orders and microchip money, it grew by 19,000.

But in 1982-83, when a 19 percent mortgage seemed like a good deal? Only 5,805 new people appeared in the county.

Still, a central question emerges, one that never shows up in the 122-page growth-monitoring report. Who are these people?

One particular area near Marysville gives some insights.

The streets around Fourth Avenue Northeast and 114th Street Northeast, on a hillside west of the city, are so new they're not on most maps, and they aren't filled with cars with license plates from Texas, California and other states, though there are some of those.

Talking with the new residents shows that some nonnumerical values — having a bigger yard for the kids, for instance — are about as strong an incentive for moving as getting another job. The conversations also reveal factors that aren't in tabular charts, such as Oregon's taxes and the Olympic Peninsula's medical care.

The area at that intersection is a development called Aspen, 440 acres turned into 190 building lots.

People started moving into the first houses about a year ago. Two more divisions are being built now, with foundations going in and framing starting to rise.

If someone stops at Fourth and 114th, within a few hundred feet they'll find people with differing reasons for choosing Aspen, yet all of whom count it as one of the major decisions of their lives.

An example is a retired Los Angeles police officer who says he barely knows what county he lives in and that it makes no difference whether it's this county or the next one to the north, which he can't identify.

"Snohomish County didn't mean anything to me," said the ex-officer, who asked that his name not be used because of his former undercover work.

He had heard about and visited Sequim on the Olympic Peninsula, where he asked what would happen if he had a heart attack. He was told how easy it would be to get flown by helicopter to someplace with advanced medical care.

"I said, 'This is not for us,' " he recalled.

Nor was Oregon because of its state income tax.

The retired officer and his wife were shown places with acreage, which they had no use for.

"Being a city slicker, what would I do with 5 acres?" he asked.

"We did our homework here," he said. "All these play a role."

What about the sunshine or the lack of sunshine?

Compared with California, he said, Snohomish County is wonderful, a place to escape years of heat and sun.

"I love this place — it's so tranquilizing," he said.

All of the homeowners mention something else that has happened: instant equity.

They drive out of their section of Aspen and go north, over streets where the sidewalks are still being poured and roofs are just being installed.

Little boxes filled with brochures in front of the houses describe the new offerings, including the $500,000 to $600,000 price tags.

"House prices aren't as bad as Southern California," said the former cop. "Here, you can see prices starting to climb. They're $200,000 more than Phase 1."

That's about a potential 50 percent profit in barely a year for the early Aspen buyers, something all of them mention as one of the unexpected benefits of moving to the area.

"I love it up here," the ex-cop said.

Peyton Whitely: 206-464-2259 or pwhitely@seattletimes.com