text: Quality Spread Distribution Page
  This page shows the overall state of the stations that have signed up for
  weather quality emails. It shows the mean error and the standard deviation for their
  readings. The worst 5% of stations are not plotted (otherwise the outliers mess up
  the autoscaling). The period of the analysis is the last 14 days.
  Note that the error is "analysis - observed". I.e. if the error is positive, then
  this means that the reading was less than the expected value.
  The specific sites that are of interest are marked in a different color.
  Comments, problems etc to Philip Gladstone
  Last modified Tuesday, 14 October 2014