How rare are the 1991 UD 20th Anniversary cards?

[ManInTheMirror]

Just trying to get somewhat of an idea how rare the 2011 cards are.

[HBMC]

Which ones? The base aren't at all.

[ManInTheMirror]

https://comimg.azurewebsites.net/i/Football/2011/Upper-Deck-1991-UD-20th-Anniversary/20A-102/JJ-Watt.jpg?id=b68603cf-4392-4fd2-b652-714d7017754d&size=zoom

[HBMC]

Ah, those. Those aren't too tough to find.

[The Card Album]

If you have a hard time finding one, it's probably only because they're so cheap and plentiful that nobody bothers with the effort of listing them anymore.

[ManInTheMirror]

Ah, well I actually own the one shown. Just could not remember how often they fell in packs. Just trying to get a general idea.