subtract 10%iles   -0.0315619      0.00000  0.000683516    0.0300451
    0.0690918     0.121037     0.198723     0.336925     0.683296
diff 10%iles    -0.284905    -0.119242   -0.0517229   -0.0125475      0.00000
   0.00895572    0.0462941     0.111587     0.276921
stardiff 10%iles   -0.0465675   -0.0172342  -0.00570842      0.00000
      0.00000   0.00536562    0.0123706    0.0232667    0.0489847
stardiff contour -excluded 0.005   -0.0465675    0.0489846