Just downloaded the 9 Jan 2005 FAA Registration Database.

As of 9 January, there were 27,614 Experimental/Amateur-Built aircraft
registered in the US. This was an increase of 3.8% over the previous year.
Here's a summary of the past four years:

Year Increase over previous year
2001 5.5%
2002 4.6%
2003 3.4%
2004 3.8%

So 2004 was a bit of a bump upwards, but not by much. However, the percentage
of homebuilts vs the overall fleet is still rising:

Year Percentage of total aircraft registered
2000 7.5%
2001 7.7%
2002 8.0%
2003 8.2%
2004 8.5%

Going to back to the changes between January 2004 and January 2005:

A total of 1,453 Exp/Am airplanes were added to the roster since January 2004,
and 432 were removed, leaving a net increase of 1021. Of the 1021 net
homebuilts added to the rolls in 2004, almost 40% (445 added, 44 removed) were
RVs!

New registrations of common aircraft during 2004:

RV: 445
Challenger II: 30
Glasair: 19
GlaStar: 15
Rotorway Exec: 36
Kitfox: 34
Lancair: 52
RAF: 14
RANS: 47
Searay: 21
Sonex: 21
Zenair: 61

(Figures are approximate due to naming inconsistencies)

Ron Wanttaja