On Tue, 22 Sep 2009 08:24:38 +0100, Brian Wakem wrote:

Must be close to modern-day high?

What that graph doesn't give you though is any sense of year-to-year
variance, which I suspect is quite marked. The 79-00 average would
have been better plotted as an envelope with say +/-2SD shown above
and below the average line. I'm guessing that the 2009 data wouldn't
then stick out as noticeably (if indeed a 2-3% deviation is
significant anyway).

JGD