Job vacancies in Minnesota were 20% higher at the end of 2018 than a year earlier, as demand surged and workers and employers tussled over wages.

The state’s jobs agency said Thursday that Minnesota employers had nearly 137,000 job openings at the end of the year, up from 114,000 at the end of 2017 and well above the level of unemployed people in Minnesota, which stood at 99,000 in December.

That means there were 1.4 job openings for every unemployed person in the state at that time. About 4 of 10 of the jobs were part-time work, defined as involving fewer than 35 hours a week.

“Minnesota continues to experience strong hiring demand statewide,” Steve Grove, commissioner of the Minnesota Department of Employment and Economic Development, said in a statement.

The tightening was also visible in another measurement: There were 4.9 job openings for every 100 jobs in the state, up from 4.2 openings per 100 at the end of 2017.

Wages also continued to climb, the new data showed. At the end of 2018, the median-wage offer for all job vacancies was $15.01 an hour. That’s up from $14.34 an hour at the end of 2017 and $13.97 an hour at the end of 2016.

But the ongoing rise in vacancies also suggests that some employers are resisting raising wages at a pace that’s fast enough to fill the positions. Earlier this week, Ron Wirtz, an economist at the Federal Reserve Bank of Minneapolis, wrote an online article describing evidence the bank gathered of the tension between prospective workers and employers in the five states where it oversees banking.

Some employers appear to be holding out for a return to a market in which more people are looking for jobs. The Minneapolis Fed’s “ad hoc” surveys show “some anchored wage expectations that are relatively insensitive to data showing persistently low unemployment and high job openings,” Wirtz wrote.

On the other side of the tension, Wirtz said, “strong hiring conditions also allow workers to be picky, even brash, with their newfound leverage.”

He cited a Twin Cities recruiting firm that said job candidates in Minneapolis began demanding a $15 hourly wage even though the $15 minimum wage that the City Council approved in 2017 doesn’t reach that threshold until 2022.

Vacancies grew at a slower rate in the seven-county Twin Cities metro area than in the state’s other 80 counties. But the metro area also had fewer people to fill jobs than elsewhere in the state.

Statewide, the employment sector with the most job vacancies was health care at 18%. Retailers reported a vacancy rate of 13%, food service 12% and manufacturing 8%.

Small employers, those with less than 50 jobs, had a vacancy rate of around 7%, more than twice as high as the rate at companies that employed at least 250 people.