installation of Percona on Centos 5.9

i am still a bit confused.
i have been using this guide
docs.1h./com/Percona_MySQL_installation_tutorial
I am having mysql ver 14.14 distrib 5.1.66
what version of percona should i install
yum --disableexcludes=main install Percona-SQL-server-SET-CORRECT-VERSION-HERE

Hi,

Generally, you should always go with the latest version as many bugs will be fixed in that.

http://www.percona.com/doc/percona-server/5.1/installation/y um_repo.html
http://www.percona.com/doc/percona-server/5.5/installation/y um_repo.html