subtract 10%iles      0.00000    0.0267529     0.117491     0.211403
     0.332337     0.501436     0.760633      1.21151      2.22456
diff 10%iles    -0.471873    -0.200175   -0.0868559   -0.0196111      0.00000
    0.0181122    0.0845706     0.196169     0.464523
stardiff 10%iles   -0.0651762   -0.0241860  -0.00755394      0.00000
  0.000718355    0.0100220    0.0214987    0.0391882    0.0796753
stardiff contour -excluded 0.005   -0.0651762    0.0796753