The percentage of people age 55 and older in the workforce is at its highest level in more than 35 years, according to a new report.

The Employee Benefits Research Institute says the percentage of people age 55 and older in the workforce reached 40.2% in 2010. In 1975, 34.6% of people age 55 and older were working. That percentage declined to 24.9% in 1993, but since then the rate has steadily increased.

Additionally, for workers near retirement age (55-64), the labor-participation rate increased almost solely because of the increase of women in the workforce, as the rate for men was flat to declining. However, the rates for men and women age 65 and older increased.

EBRI also found that education is a big factor for older individuals staying employed: Those with higher levels of education are more likely to stay at work than those with lower levels of education.

The analysis is based on the U.S. Census Bureau's data on labor-force participation among Americans age 55 and older, and focuses on what happened to trends after the economic recession that started in late 2007-early 2008.