I am sorry for not making any professional comments (I am not a pilot) but I continue to be interested and to learn from what is posted here. But, I tend to disagree with the statement:
"how many of those failures occured on twins maintained to ETOPS standard, how many occured in ETOPS sectors and how many resulted in a hull loss".
Is it not true that airplanes today are so safe that a problem is not likely to develop into a "hull loss". Does it imply that there is nothing to be improved? Perhaps that counting "hull losses" is not good enough to measure safety?