With the help of archive.org, here are Van's stats for the size of the
RV fleet at various dates:
1/20/99: 1862
1/4/01: 2568
1/17/02: 2808 
8/22/03: 3365

Using http://www.ntsb.gov/ntsb/query.asp query for type == "rv",
which produces a few false positives...

year 2001 had 17 RV accidents, 6 fatal, 8 deaths

Suspected causes (my analysis using NTSB probable cause if available):

unknown systems problem: 1(engine) 2(engine fatal) 3(engine) 4(engine)
other unknown: 1(jackpot fatal -- claims of pilot error on the web)
system or design failure: 1(rv8 stick design)
pilot error, normal ops: 1(landing) 1.5(collision on runway) 2(stall/MJ fatal) 
            3(headset on floor) 4(flare) 
            5(student/flare) 6(icing fatal) 7(flare)  
            -- 8 total, at least 4 seem unrelated to RV
pilot error, maneuvering: 1(baker overflight fatal)
mechanic error: 1(no oil) 2(homebuilt engine)

How many hours per year do GA aircraft fly?
FAA est 26.2 million GA flight hours in 2001 (1494 accidents in 2001)
FAA says 16739 amateur-experimental a/c in 2002, 149K ASEL production A/C,
182K fixed wing GA --> 143 hours per AC per year across all of GA
(including corporate aviation which probably flies more hours per year
than average)


if you use 143 hours/AC/year you get 367224 RV hours flown/year ->
.04 accidents per 1000 hours, 4.6 per 100K hours.

Fatal accidents at about one third that rate.

According to the 2001 Nall Report, the overall GA accident rate was 6.56 
per 100K hours flown, 1.22 fatal per 100K hours flown.  So the RV rate
does not seem out of line with the overall fleet, but there is a lot
of potential error coming from the hours flown per year measurement.
Who knows how many hours RVs fly per year?  100 or less would be my
guess...

Accident detail, a relevant quote from the NTSB finding followed by
injury data and my comments in parens:

#1: the pilot's inadequate recovery from a bounced landing, which
resulted in a hard landing and collapse of the nose landing gear.
(1 serious, 1 minor)

#2: The loss of engine power for undetermined reasons.
(1 minor)

#3: ...experienced a mid-air collision during landing flare touchdown...
(3 uninjured)

#4: the pilot's failure to perform a preflight inspection, which
resulted in a loss of total engine power due to oil starvation. A
contributing factor was the lack of suitable training for the forced
landing.
(1 uninjured, turns out the mechanic left it drained...pilot's fault too)

#5: The pilot inadvertently stalled the airplane. A factor was the
impairment due to marihuana.
(1 fatal, unclear to me if pilot was actually intoxicated)

#6: Postaccident examination of the airplane by the pilot, revealed
that a headset on the floor of the airplane had jammed the rudder
controls.
(1 uninjured)

#7: The pilot's failure to maintain control of his airplane during the
landing flare.
(2 uninjured)

#8: the loss of engine power for undetermined reasons during the
landing approach. A contributing factor was the lack of suitable
terrain for the forced landing.
(1 minor)

#9 Prelim report: On July 7, 2001, at 1412 hours Pacific daylight
time, a Johansen/Thiessen RV-6A, N246RV, collided with the ground
while maneuvering near Jackpot, Nevada. The airplane was destroyed,
and the certificated private pilot and his single passenger sustained
fatal injuries. A private owner was operating the airplane under the
provisions of 14 CFR Part 91 at the time of the accident. The personal
cross-country flight departed Jackpot earlier that day and was
presumed to be destined for Wells, Nevada. Visual meteorological
conditions prevailed at the time, and no flight plan had been filed.
(2 fatal, people on internet claim it was pilot error)

#10: the jammed elevator control stick on takeoff roll. A contributory
factor was the crosswind.
(pilot claims due to rv8 design flaw)

#11: the pilot's failure to maintain aircraft control following a loss
of engine power. A factor was the loss of engine power during takeoff
initial climb for undetermined reasons.
(1 fatal)

#12: the premature flare by the pilot.
(1 serious, student pilot)

#13: The engine failure for undetermined reasons. Factors were the low
altitude, the trees, the presence of the irrigation system, the ditch
and the soft ground.
(2 minor)

#14: prelim report: A sheriff's deputy interviewed the pilot's
son. The pilot delayed his departure from Chino due to weather. He was
to over fly the son at a retreat so the son would know to pick him up
at Baker. The son said that as the airplane passed over, it rolled to
the left, and then sharply to the right before descending to the
ground.
(1 fatal)

#15: the in-flight collision with mountainous terrain during a forced
landing following a loss of engine power resulting from the pilot's
inadequate weather evaluation, continued flight into icing weather
conditions, his delay in carburetor heat use, and his delay in
diverting to an alternate airport.
(2 fatal)

#16: The pilot's improper flare, and his evaluation of the gusty wind
conditions resulted in the collision with the terrain.
(2 minor)

#17: The total loss of engine power due to fracture and separation of
the engine crankshaft.
(2 uninjured, non-A&P owner built engine from scratch out of lycoming parts)

all fatals were rv6, other accidents: 1 rv8, 1 rv4, 2 rv3


More from the 2001 Nall Report:

HOMEBUILT AIRCRAFT - Comparison with Factory Aircraft 

In 2001, homebuilt airplanes were involved in 184 accidents. Of these,
51 fatal accidents resulted in 68 fatalities. Factory-built airplanes
in 2001 were involved in 1,310 accidents, of which 247 were fatal with
467 fatalities. Nearly 30 (27.7) percent of homebuilt aircraft
accidents resulted in fatalities, and 18.9 percent of the accidents in
factory-built airplanes were fatal. As in prior years, it appears that
there is a significantly higher risk of a fatality in the event of an
accident in a homebuilt aircraft compared to a factory-built
machine. The fatality rate for homebuilt aircraft increased seven
percent in 2001. Although fatal homebuilt aircraft accidents decreased
dramatically in 2000, they increased to 17.1 percent in
2001. Historically, homebuilt aircraft are involved in approximately
16 percent of all fatal accidents.

MAJOR CAUSE       ALL ACCIDENTS FATAL ACCIDENTS 
Unknown                1.6%         5.9% 
Other                  13.0%        15.7% 
Mechanical/Maintenance 24.5%        15.7% 
Pilot                  60.9%        62.7%