That does sound high, are they including loss (ie running out) of power in that statistic?
Robbies in particular seem to have many power loss accidents with fully operational engines.
Is that because pilots think if they can get under the line on the HOGE graph, they can do anything they like? Any OGE operations should have a power margin available to allow for pilot errors, wind, turbulence, imperfectly clean blades etc etc
Standard UK mil ops require a minimum of a 5% thrust margin - it is easy to calculate, you just reduce your AUM by 5% of the maximum HOGE graph value at your intended operating DA.