Does/Can PG store administrative statistics?

I'd like to have statistics on when my database was last backed up or
vacuumed. Currently, I'm implementing this by using simple shell
scripts that write a date stamp to ascii files. I was wondering
whether this is or could be a feature added to Postgres?

For example, could one of the pg_* tables contain the fields
'last_vacuum' or 'last_backup' (which would be updated every time the
vacuum or pg_dump command was executed).

Perhaps something like this exists that I'm unaware of?

-Tony