Despite such gains, preprimary enrollment in the United States is below that of many other developed countries, especially in the years before kindergarten.
One factor in the growth in preprimary enrollment in recent decades has been an increase in the number of women with young children entering the work force.
The National Center for Education Statistics (NCES) of the U.S. Department of Education reported that the proportion of U.S. children aged three to five who were enrolled in preprimary programs more than doubled between 1965 and 1990, and as shown in Figure 1, modest gains continued in the 1990s.