From the Bureau of Labor Statistics:
Between 1979 and 2011, the earnings gap between women and men narrowed for most age groups. The women’s-to-men’s earnings ratio among 25- to 34-year-olds grew from 68 percent in 1979 to 92 percent in 2011, for example, and the ratio for 45- to 54-year-olds increased from 57 percent to 76 percent.
In 2011, among the age groupings of those 35 years and older, women had earnings that ranged from 75 percent to 81 percent of those of their male counterparts. Among younger workers, the earnings differences between women and men were not as large.
At each level of education, women aged 25 years and older have fared better than men with respect to long-term earnings growth. Although both women and men without a high school diploma have experienced declines in inflation-adjusted earnings since 1979, the drop for women was significantly less than that for men: a 10-percent decrease for women—as opposed to a 33-percent decline for men.