Pete and All,
 My records show that a few ( about 2% )  made it 3 years. It is interesting to track the source and breed. You can see a difference but you have to balance it against the weather for any given year. The one thing that shows up is after 1990 all the queens went down. I had only one line that stayed firm for 3 years and that was some carniolans  from one breeder in California. 
 I do not think that longevity is a real problem. If you can get through one year with a strong hive with a good solid brood pattern , your doing OK. I do like it to go into the second year if possible. The problem now is that brood patterns are not good compared to years ago.  I have pictures that show and solid brood pattern on both side of a deep frame. No holes. I have not seen that for a long time. 
 The problems with queens are not new. In my 1884 Hive and Honeybee  they mention some problems going back to 1790. History repeats itself. The problems may change do to the environment we have for the bees. That is why it is important to document  any changes in management practices .  It is liking a backup for your computer.  I have made some bad turns over the last 44 years. I have been able to see the cause and affect of my changes. Some were not good.
 One thing I'm sure of and that's Nature is always changing. We do one thing and she responds in her way.  That dates back to Darwin and the idea of evolution. It will keep going on as we scratch our heads . That is why I love beekeeping , so much to learn.
Best Regards
RoyNerttlebeck  

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