---------all data----------------------- 
layer frac-ave   frac-sig   median-seeing
0001 2.40000E+01 2.70000E+01 4.80000E-01
0002 5.00000E+00 1.10000E+01 4.80000E-01
0003 1.10000E+01 1.30000E+01 4.80000E-01
0004 1.90000E+01 1.70000E+01 4.80000E-01
0005 2.40000E+01 2.00000E+01 4.80000E-01
0006 1.40000E+01 1.00000E+01 4.80000E-01
---------best 30 percentile--------------
layer frac-ave   frac-sig   median-seeing
0001 1.30000E+01 1.80000E+01 3.60000E-01
0002 3.00000E+00 7.00000E+00 3.60000E-01
0003 9.00000E+00 1.30000E+01 3.60000E-01
0004 2.00000E+01 1.60000E+01 3.60000E-01
0005 3.00000E+01 2.10000E+01 3.60000E-01
0006 2.30000E+01 1.10000E+01 3.60000E-01
---------worst 30 percentile------------ 
layer frac-ave   frac-sig   median-seeing
0001 3.90000E+01 3.20000E+01 7.10000E-01
0002 9.00000E+00 1.30000E+01 7.10000E-01
0003 1.30000E+01 1.30000E+01 7.10000E-01
0004 1.60000E+01 1.80000E+01 7.10000E-01
0005 1.30000E+01 1.30000E+01 7.10000E-01
0006 7.00000E+00 5.00000E+00 7.10000E-01
6 layers (centered at h=0.5-1-2-4-8-16km, thickness=3h/4)