The growth of education is strong throughout the world as we move towards the future, not only in developing countries but also among women, who make us more than half of the current pool of students. Not only has access to education doubled since 1970, but the efficacy of such programs is increasing as well. We're also spending more time in academia overall, with our expected education life lasting an average of 16 years in North America. Although the United States is in the middle of the pack in primary and secondary education when compared internationally, our post-secondary institutions are some of the best in the world. 22% of the best colleges and universities are on our soil. Because of that, the number of international students at our institutions has increased significantly since 1950. 600,000 students are estimated to come from other countries as of 2011.