The number of nonfarm jobs in the Lafayette metro area increased by 13,500 from December 2011 to last month, according to figures released Friday by the Louisiana Workforce Commission.

That 8.6 percent gain put the Acadiana area at 170,000 jobs. The city saw widespread job gains, with mining and logging, which includes oil and gas extraction, going from 16,900 jobs to 19,700 and professional and business services adding 2,300 jobs to 20,300.

Economist Loren Scott said the Lafayette numbers were “hard to believe.”

While the economy is strong, thanks to increased activity in the oil and gas industry, numbers such as sales tax collections and home sales don’t reflect a market that’s posting 8.6 percent annual job gains, he said. The discrepancy in local numbers could be caused by a change in how the numbers are collected, Scott said. The U.S. Bureau of Labor Statistics took over the process more than a year ago. Before that the figures came from the Louisiana Workforce Commission.

Another factor in driving up the Lafayette job numbers could be caused by people working in hot natural gas markets such as North Dakota and Pennsylvania, Scott said.

“A lot of people over there are working for folks like Stone Energy and PetroQuest, and they may be counted to be working in Lafayette,” he said.

New Orleans added 1,100 jobs from December, bumping the Crescent City up to 530,400. That was an increase of less than 1 percent. Baton Rouge was unchanged during the same period, staying at 371,400

Other Louisiana metro areas to post job gains in December were Houma-Thibodaux, which added 2,000 jobs in the 12 month period to top 97,700; Monroe, which added 1,400 jobs to come in at 78,400; and Lake Charles, which was up to 89,300, 1,000 more than the year before.

Shreveport-Bossier City, which was hit by the recent closing of a General Motors plant, dropped to 177,900 jobs in December from 179,000 in 2011. And Alexandria posted a modest 200-job decrease, going to 63,200.

Louisiana saw the number of nonfarm jobs increase by 23,600, or 1.2 percent, over the year, putting the statewide total up to 1,961,500.

“That’s a record level for us,” Scott said. “We’re getting real close to the 2 million job mark.”

Louisiana is on track to top 2 million jobs by the end of the year or early 2014, thanks to the booming chemical industry, he said.

Scott said Louisiana is one of the few states that has seen an increase in jobs since the start of the Great Recession.

“I was in Alabama this week for a speech and they’re still 100,000 jobs below where they were in 2008,” he said.

Statewide the unemployment rate was 5.5 percent. The figure is not seasonally adjusted. Lafayette’s unemployment rate was 3.7 percent. Baton Rouge had a 5.4 percent rate, while New Orleans was at the state average at 5.5 percent.