...and that's while currently taking into account of the Solar Flare forecasts when heading over the poles.
Just to clarify my comment above, it looks like the study may not have looked into Polar transits, which of course hold a much higher intensity and risk. On those trips Solar Flare forecasts are referenced at the planning stage.
A simple little article to explain:
http://www.avweb.com/news/aeromed/18...l?redirected=1
Further references:
http://www.swpc.noaa.gov/NOAAscales/...adiationStorms
http://www.denvernaturopathic.com/ne...ileflying.html