From examining the AAIU website (Helicopters only):
27 x EI-Reg Acc/Inc (15 Acc)
13 x G-Reg Acc/Inc (7 Acc)
4 x N-Reg (3 Acc) (Not including Bettystown)
Summary out of the full list of reports, assuming this is complete.
None of the N-Reg accident/incidents was maintenance related.