Utah experienced its single largest increase in taxable sales in more than a decade last year, according to a new report.

Wages are up and tourism and business both saw gains, all indicators of a strong economy, analysts said. The numbers are predicted to continue to rise over the next year, although at a slower rate.

The state's taxable sales increased by 11.1 percent to $3.9 billion in 2005 — the largest single-year growth since 1993, according to an Office of Legislative Research and General Counsel report.

"It was very surprising. And the reason for that was one of the drivers of this growth was business investment," Robert Spendlove, Utah director of demographic and economic analysis, said Wednesday. "Essentially what happened is we had corporate income taxes and capital gains taxes skyrocket with the recovering economy. . . . They put that back into business investment."

Larger increases in taxable sales have only occurred three other times in the past 25 years.

"Given the rarity of such a high rate of growth, the rates of increase will likely slow down in 2006," the report said.

The past year was a banner year for economic growth in Utah and gave legislators more than a $1 billion budget surplus. The state's job growth of 3.5 percent was more than double the national average. Legislators will meet again this spring to discuss cutting $70 million in taxes by overhauling the state's income tax code.

Salt Lake, Utah and Washington counties made up 65 percent of the state's taxable sales, but only Washington County was among the 10 counties experiencing the fastest rates of growth.

Washington County is increasingly becoming an economic and employment center of the state, Spendlove said.

Daggett County, which saw its taxable sales increase by 150 percent, led the state in growth. Along with Juab County, Daggett County has consistently outpaced the rest of the state with an average growth rate of more than 20 percent since 2000.

The report said retail sales made up 46 percent of all taxable sales, but other industries also showed strong growth, including transportation, mining and construction. Business service purchases grew by 21 percent in the past year and make up 15 percent more of the state's overall taxable sales than they did a year ago, according to the report.

Much of the economic growth in the past year can be attributed to the state's growing population, economists said. In 2005, Utah was the fifth-fastest growing state in the nation. The largest single in-migration of new residents in the state's history also helped spur a $6.4 billion construction boom in 2005, according to an economic report for the governor. Most of that construction, $4.5 billion worth, was residential.

Construction spending is expected to increase 7.4 percent this year.

In the past year, Kennecott Land announced plans to develop 75,000 acres in the West Bench area of the Oquirrh Mountains over the next 50 years. Fully developed, it would be twice the land area of San Francisco and home to about 500,000 people.