From what I have seen, the average varies from 1 to 5 years of
J2EE experience. Not all of them may be working as architects, in fact you will find a great number of wannabe architects who are currently working as senior designers.
In general I have found that real-life experience in designing and developing J2EE based applications is necessary for solving Part II and Part III. That does not mean it is a must, but it will greatly enhance your ability to solve the assignment.
I am waiting for my part II and III results, I have about 5 years of J2EE experience, and I am currently working as an architect.
Hope that helps,
