I still don't have an answer to Jerome's question: how do you get from the numbers in that table to the conclusions drawn by Hughes.

Or, as a well-defined subset of that question, I wish I had some sort of explanation for how you can get the assertion

The decline in the normalised load factor for Danish onshore wind farms is slower but still significant with a fall from a peak of 22% to 18% at age 15

from my graph (which contains all the relevant data : yes it's a very small data set for such a big conclusion.)

What I find particularly annoying is that initially, people here accepted his conclusions at face value and tried to find excuses for the dramatic declines he asserts.

_{It is rightly acknowledged that people of faith have no monopoly of virtue - Queen Elizabeth II}