Orbert, while I get where you are coming from, I disagree with several things there.
First, Rabin has actually been on four albums (Union isn't very good, but it counts), but that aside, all tenure is not measured the same way. Rabin was on, and was the main songwriter, two albums which had some of their biggest hits ever (90125 and Big Generator), while Downes was on three albums that didn't make a dent at all (except Drama, which is liked by some hardcore fans like us quite a bit). Impact, success and relevance matter much more than tenure, more often than not.
Second, I think we all tend to worry too much about "original members." I mean, does that really matter that much? Peter Banks is an original member, but he is more Yes than Rick Wakeman, Trevor Rabin or Steve Howe? Hell no. To me, with Squire gone, Anderson, Howe, Wakeman, White, Bruford and Rabin are the six who I look at as true Yes guys who are currently alive.