The number of online help-wanted ads in Ohio is at its highest level since 2005, reflecting a surge in demand for workers across the state, The Conference Board reported Monday.

The number of online advertised vacancies in Ohio grew by 7,000 to 188,900 in April — the highest level since the nonprofit business research group has been tracking such data for the past seven years.

Employers advertising online in Ohio have added 20,600 listings during the past three months with the metro areas of Cleveland, Columbus and Cincinnati adding 5,800, 4,800, and 2,700, respectively.

In the Dayton-area, the number of online job listings dipped by 150 last month after reaching a peak of 14,273 in March. Labor demand in the Dayton area has grown by an average of 460 online advertised vacancies during the past six months, the Conference Board reported.

“What they’re seeing is the same thing that our forward-looking survey indicated would happen,’’ said Tom Maher of Manpower of Dayton, the local franchise of international employment services firm, Manpower Inc. “The employers that we spoke with going into (the second quarter) were quite optimistic, and it looks like they they’re putting their money where their mouths were.’’

Still, the number of unemployed exceeds the number of job openings by a ratio of more than 2-to-1 in the state and local area. Nationally, the ratio is closer to 3-to-1.

Across the country, online labor demand grew by 90,900 to more than 4.8 million job listings last month, also an all-time high, based on Conference Board figures. That brought the national supply/demand ratio to 2.7 unemployed workers for every vacancy.

The Ohio rate was slightly lower at about 2.3 unemployed workers for every online job listing, and 2.4 unemployed for every opening in Dayton, based on March employment figures from the Ohio Department of Job and Family Services.

“The problem that we’re still facing is the mismatch between the skill sets of those who are unemployed and what employers are looking for,’’ Maher said.

Some labor market experts attribute at least part of the gap in job openings and available workers to lower wages in former high-paying industries like manufacturing that have kept some workers on the sidelines.

“We’ve definitely seen a re-set of wages in this community and throughout the country,’’ Maher said. “If your previous experience was in a manufacturing environment with the General Motors facility, then the wages and benefits being offered now by local manufacturers are significantly different.’’

The most recent report from OhioMeansJobs, the state’s online job board, found that nearly a quarter of all online job listings in the Dayton area were for entry-level jobs — such as retail sales, food service industry and customer service representatives — that paid less than $30,000 annually.

However, the largest share of positions advertised online were upper-middle-income jobs that paid between $50,000 and $79,000 a year. Upper middle income jobs also made up the largest share of statewide job listings in March, OhioMeansJobs reported.