Here are some numbers for the US from a NTSB Database Search I did.
Leading Causes of Fatal Turbine Rotorcraft Accidents (US) 2004-2014
Fatal Accidents (totals past 10 years) (108)
Collision with Wires/Obstacles 26
Inadvertent IMC 15
Main Rotor Blades/System Failure 9
Spatial Disorientation 9
Mid Air Collision7
Fuel Exhaustion5
Engine Failure Mechanical (Single Engine)5
Undetermined 5
Pilot Medical Incapacitation 3
Over Gross Weight CFIT3
Tailrotor/Drive Failure3
Dynamic Rollover 2
Undetermined (Not Engine Related)2
Passenger Bumped Controls2
Ground Personnel Contact with Rotors2
Failed Attempt at Aerobatic Maneuvers2
Ext. Load Contacted Tail rotor 1
Hydraulic Failure1
Bird Strike1
Engine Failure (Twin engine Helicopter)1
Twin engine helicopter took off with one engine at idle (CFIT)1
Controlled Flight into Water While Filming1
Took off with Pedals Locked1
Loss of Tail rotor Effectiveness1