Enhancement pack to SAP Basis version

Hi,

I would like to know EHP is linked to what version of SAP Basis release.  When you install EHP6 you see Basis Version 7.31.

Please let me know for following:

     ECC EHP1 - SAP Basis Release: ?

     ECC EHP2 - SAP Basis Release: ?

     ECC EHP3 - SAP Basis Release: ?

     ECC EHP4 - SAP Basis Release: ?

     ECC EHP5 - SAP Basis Release: ?

Thanks,
Digesh