Also don't forget that the counters aren't 100% reliable. For instance I see "Tin tức (100)" on
http://dmoz.org/World/Vietnamese/ , but "Tin tức (102)" on
http://dmoz.org/World/Vietnamese/Tin_tức/ . The correct number of listed sites in Vietnamese is currently 777 (from an editor-only counter that
is accurate).
Also, just because the number doesn't change (by much) doesn't mean that sites aren't being added and removed in roughly equal amounts, or perhaps existing listings are being updated. I'm not saying that this is necessarily the case here, but you shouldn't just rely on those numbers when making judgements.
Perhaps better is to look at the "last edited" date at the bottom of each page. This gives you the last date on which any editing action (add, delete, change) was performed in that category. (It does
not mean that the whole category was reviewed on that date, or that all the public suggestions prior to that date have been either accepted or declined.) The absence of a date means that nothing has been done since our servers came back in January 2007 following the "big crash".