How can I upgrade my 9.0.93 to 0.94 by yum?

[hutuworm <hutuworm hz cn>]

How can I upgrade my 9.0.93 to 0.94 by yum?
When I run yum upgrade in my 9.0.93 box, it returns :
<quote>
Gathering header information file(s) from server(s)
Server: Red Hat Linux 9.0.93 - i386 - Base
retrygrab() failed for:

http://mirror.dulug.duke.edu/pub/yum-repository/redhat/9.0.93/i386/headers/header.info
  Executing failover method
failover: out of servers to try
Error getting file 
http://mirror.dulug.duke.edu/pub/yum-repository/redhat/9.0.93/i386/headers/header.info
[Errno 4] IOError: HTTP Error 404: Not Found
</quote>
And I found there's no such a directory named 9.0.93 but 0.94 under 
http://mirror.dulug.duke.edu/pub/yum-repository/redhat/