maybe here in Belgium we are learning very slowly....I am 2nd kyu with over 5 years of aikido under my belt, and we also have other 2nd kyus with 8 years of training. I never knew anyone who got 2nd kyu after 2 years, but two or three people who got 3rd kyu after 2 years, which was already considered an achievement. This applies for people training 2 - 4 times per week.
I have been training for going on 3 years 3 days/6 hours a week. Will be testing 2nd kyu this spring. I guess a lot has to do with the affiliation and style as well as who your teachers are as to what time period is expected for testing.