Hi,
the *-pgdg distributions on apt.postgresql.org always only contain the
most recent version of each package. Older versions are removed
automatically by reprepro when newer versions are added.
Users have often asked about older versions of packages. These have
always been stored in a "morgue" directory on the repository master
host, but were not available publicly. This has been changed now:
http://atalia.postgresql.org/morgue/
There is no dists/ structure, and the provided Packages.xz and
Sources.xz files contain all packages for all distributions, users
will need to choose the correct files manually.
https://wiki.postgresql.org/wiki/Apt/FAQ#Where_are_older_versions_of_the_packages.3F
(Technically, reprepro stores everything in a single flat morgue
directory, the pool-like structure with subdirectories is implemented
by a shell script at
https://git.postgresql.org/gitweb/?p=pgapt.git;a=blob;f=repo/bin/morguefiles-to-pool
that is run hourly.)
Christoph