As commented by @shoover:

I think the date is Dec 2. Look at the "I hereby certify..." near the bottom of the page.

and if it is Dec 2 then, unlike Dec 21, that is before and not after the other two dates of Dec 14 and Dec 18.

The date you have read as Dec 21 appears to me like it could possibly be a 2 with a long upstroke at its end that just looks like a following 1.

As commented by @shoover:

I think the date is Dec 2. Look at the "I hereby certify..." near the bottom of the page.

and if it is Dec 2 then, unlike Dec 21, that is before and not after the other two dates of Dec 14 and Dec 18.

The date you have read as Dec 21 appears to me like it could possibly be a 2 with a long upstroke at its end that just looks like a following 1.