From 1975 to 2004, the labor force participation rate of mothers with children under age 18 rose from 47 to 71 percent, according to the Bureau of Labor Statistics. And while the availability of child care subsidies has increased dramatically in recent years, the Urban Institute reports that nationally only between 10 percent and 15 percent of eligible children benefit from child care subsidies from the Child Care and Development Fund, the main source of federal funding for this help.