The graph shows the enrollment ratio vs female age at first marrieage in OECD countries. The source is the new paper "Gender Differences in Education" (February 2012) by Tuomas Pekkarinen.
The paper concludes:
The rapid growth in female educational attainment is one of the most striking trends in education statistics in the post WWII world. In an increasing number of industrialized countries female educational attainment is now higher than male educational attainment. Women are in majority among secondary school graduates, among tertiary level students, and among tertiary level graduates. Judging from recent trends in international data, it seems likely to that female dominance in educational attainment is becoming stronger in the coming decades.