I can give you the final statistics for the approximately 5 months in which FET-5.14.3 was the available version (a version which stood here for a very long time):
Date - Windows exe - sources tar.bz2
main (lalescu.ro):
2010-11 - 3904 - 994
2010-12 - 3972 - 870
2011-01 - 6403 - 993
2011-02 - 4575 - 866
2011-03 - 6242 - 725
mirror (timetabling.de):
2010-11 - 1020 - 542
2010-12 - 761 - 471
2011-01 - 1453 - 514
2011-02 - 1339 - 510
2011-03 - 725 - 388
Total Windows exe: ~ 24394 correct, ~ 6000 fictive (~ 30394 total), see Note2 below
Total sources tar.bz2: ~ 6873 downloads
Note: I can safely say that there were at least 24394 correct downloads. It is incorrect to add the Windows exe downloads with sources tar.bz2 downloads, because many users are downloading both, and many are downloading sources tar.bz2 and they see that they need in fact the Windows exe, so they download also the Windows exe after that.
Note2: Maybe ~6000 downloads for Windows exe are fictive, because I noticed sometimes from the same IP many downloads (like an IP downloading 1000 times the Windows exe file - there were about 3 situations like that, and in March I noticed a single IP downloading in a single day 2900 times the Windows exe). So, 30394 total - 6000 fictive = 24394 correct.
Note3: Some GNU/Linux distributions offer FET as precompiled packages - these are of course not counted. Would be interesting to have these - could you help? Also, some other pages are hosting their own mirrors - these are again not counted. For instance: http://download.cnet.com/FET-Free-Timetabling-Software/3000-2124_4-10759044.html?tag=mncol&cdlPid=10879276 and http://sourceforge.net/projects/fet-timetabling/
I updated the final statistics for FET-5.14.3 downloads, please see the first post in this thread.