Not really... It's pretty short, actually...
All depends on the dojo and the environment. I've been beaten up by a 10 year sandan - all her 10 years at Aikikai Hombu in Shinjuku.
I, on the other hand, started in 1993, already had a shodan from judo, spent 6 years as a san-kyu, (long story during which I very nearly hung up the obi). Shodan 2007, Nidan 2009.