NEW YORK (CNN/Money) - The percentage of older workers in the economy has continued to post gains, according to a published report.

Since the March 2001 recession, there has been a 3.7 percentage-point increase in the labor-force participation rate — the proportion of the population in the work force — of people 55 and older, reflecting demographic and economic changes and lifestyle choices, according to USA Today.

Dean Baker, co-director of the liberal Center for Economic and Policy Research in Washington, said that workers 55 and older account for more than half the job gains in the past year under the Labor Department's monthly household employment survey, filling 918,000 jobs compared with an 892,000 gain for younger workers.

Also, the number of employed men 55 and older has risen nearly 20 percent since March 2001, seasonally adjusted, while the number of employed women in that age group has risen 26.3 percent. The percentage of individuals 65 and above in the workforce is now the highest since 1970.

Baby boomers are aging into the over-55 group, pushing up the numbers. The 2001 stock market drop, which hurt stock portfolios, and reductions in pension and retiree health benefits mean some might have to keep working for financial reasons.