subtract 10%iles      0.00000    0.0160718     0.102700     0.197711
     0.318855     0.488571     0.748344      1.19886      2.20361
diff 10%iles    -0.473816    -0.201330   -0.0875063   -0.0199137      0.00000
    0.0174260    0.0838711     0.195974     0.464665
stardiff 10%iles   -0.0641172   -0.0235418  -0.00729382      0.00000
  0.000646461   0.00955126    0.0204766    0.0375699    0.0769093
stardiff contour -excluded 0.005   -0.0641172    0.0769091