tertiary education

Here is an article about which countries are most educated: http://finance.yahoo.com/news/the-most-educated-countries-in-the-world.html Seems to be a bit of a cultural trend here...six of the top ten are the UK or former British colonies. At any rate, is higher tertiary education level...

...using the criteria of amount of time committment, the % of undergraduates who finish and don't switch majors, and the GPA of an average student in the major. I'm interested in peoples' opinions because I'm switching majors and feel too clueless about differences in difficulty among these.