Missing release dates

I notice for some cover listings there are entries appearing at the bottom of the list with no release date even though the year of release appears elsewhere in the database.

For example, consider the page for "High Noon":

High Noon (Do Not Forsake Me)

The entries for the versions by Frankie Laine and Bill Hayes appear in positions 18 and 19 even though it is known that they were released in 1952.

Is this an error or intentional?

Those are entries in need of revision. There have been several revisions of the database over the years. All it was before my time as an editor, these entries appear to be in the format used in the database in olden days.