I see. Well, at least for now I can add it as “undetermined” and add a note with the 2021 year. 😀
UPDATE: Or I can make a new page, or add 2021 in the years, whatever is appropriate to do.
If the type us the same you can simply request to add 2021 to the date list. In the mandatory comment box at bottom of the page, you can simply add the link to this forum thread.
The text is black on this note and green on the others and also the serial on the reverse is different. Maybe is better to create a new page for this note.