Postgres SRPMs for RHEL

Is there a reason why the source RPMs for PG 8.1.16 on RHEL don't show
up here?

http://www.postgresql.org/ftp/binary/v8.1.16/linux/srpms/redhat/rhel-4-i386/

If I cycle through the versions, the last version in the 8.1 branch I
can find with source RPMs is 8.1.14.


--
Justin Pasher