IO540,
I suppose a lot depends on whether one excludes microlights; they must get a higher % of structural failures (flying WITHIN the operating envelope I mean).
Microlights in the UK are required to meet a minimum design flight envelope of +6 and -3 G. In the flight manual this is limited to a operatin limit of +4 and -2G.
In 3 axis microlights, structural failure is as rare as it is in VLA or -23 aircraft.
Some of the older types actually come out at meeting a +8 limit and due to the high drag have to be aimed vertically down to reach VNE.
A matchstick can withstand over 100G.
Regards,
DFC