All nonprofit managers know that volunteers are an integral part of their organizations, but do they know the more minute details about them?

As determined by the U.S. Department of Labor’s Bureau of Labor Statistics (BLS), more than 60 million people volunteer annually in the country. Additional research done by Washington, D.C.-based Independent Sector showed that the estimated value of volunteer time as of 2012 is $22.14 per hour.

In the book “The Complete Idiot’s Guide to Giving Back,” Elizabeth Ziemba, J.D., M.P.H., listed some additional statistics from the BLS that shed more light on the kinds of people that are most likely to volunteer.

• More woman than men volunteer.
• Most volunteers are between 35 to 54 years of age.
• More married people than singles volunteer.
• Employed individuals volunteer more than those who are unemployed.
• People volunteer for one or two charities on average.
• Most volunteer hours are spent fundraising, tutoring, or teaching.
• Volunteers spend about 52 hours per year on volunteer activities.