The AOPA US link I quoted doesn't show exact stats, so I can't tell you if the accident rates is across the fleet, hours flown or whatever. However it does also mention the C150/152
The AOPA article quotes a stall/spin accident rate of 3.28 per 100 aircraft (Tomahawks) in the fleet compared with a figure of 1.31 for the Cessna 150/152.
"Bottom line - the Tomahawk is involved in proportionately more stall/spin accidents than comparable aircraft. Does that make it unsafe? No, it only means that the PA38 must be flown precisely in accordance with the Pilot Operating Handbook and with instructors who are proficient in stalls and spin recovery in that aircraft ..."
I don't have much faith in the integrity of the AOPA report:
I looked at the sample data used by the ASF for this report. I chose to look at the 8KCAB as I recall some of the stall/spin accidents - but not one of those was included. Of the the two that were included by ASF - one was not a stall spin accident in my opinion - a practice forced landing with a severe bounce on landing followed by impact with trees some distance further on. The second followed a failed banner pick-up. I found three more fatal stall/spin accidents in the NTSB database which should have been included. Two from low level beat-ups. One from an instructor demonstration of an inverted spin - the student survived with the use of a parachute.
I've read a lot of information on the Tomahawk stall and spin characteristics including the 7 page letter from the NTSB to the FAA - I do not intend ever flying in one and I certainly will never spin one!