There were four grades before the 2006 World Cup draw. What is the basis of grading?

Of course, we don't know that all the teams in the 2006 World Cup have not yet been produced. However, I can't think of anything bigger than these cardinal numbers: 1998 and 2002 World Cup finals and 2005 world rankings, from which we can predict the grading situation (the teams I say below are based on the assumption that they have already qualified).

The first file will include host Germany, defending champion Brazil, Italy, Argentina, France, Netherlands, Spain and England.

The second stalls will be: Nigeria, Mexico, the United States, Cameroon, Czech Republic, Denmark, Uruguay and so on.

The third gear may be South Korea, Japan and South America or Africa in Asia.

The fourth file will be the teams participating in the World Cup for the first time: Ukraine, Ghana, Iran and Saudi Arabia in Asia.