Workers in some industries are much less likely to have health insurance than workers in some other lines of work, according to the Employee Benefit Research Institute.

About 36% of the workers in agriculture, forestry, fishing, mining and construction were uninsured, compared with 22% of service sector workers, 18% of wholesale workers and only 15% of workers in manufacturing, EBRI reports.

Researchers at EBRI, Washington, came up with the figures by analyzing 2006 U.S. Census Bureau data.

EBRI also has calculated the effects of income category and employer size on uninsured rates.

Uninsured rates ranged from just 7.1% for families with annual incomes of $75,000 or more up to 36% for families with annual incomes under $10,000.

Similarly, uinsured rates ranged from 13% for employees in firms with 1,000 or more employees up to 35% for employees in firms with fewer than 10 employees.

The uninsured rate was 18% for women and 22% for men, and it was 13% for white U.S. residents, 22% for black U.S. residents and 36% for Hispanic U.S. residents.