curvature versus slope
  n = 117602 
  X=0, Y = 13.53 +/- 14.47 
  Weighted least-squares fit:  Y = 46.5 + 2.563 X  + -0.02814 X**2 

slope versus dZ, curvature < 5
  n = 24620 
  X=0, Y = 62.72 +/- 4.69 
  Weighted least-squares fit:  Y = 66.2 + 0.007 X  + -0.00034 X**2 
     at X = 100, Y = 63.6 
     Bad fit. P2 = 0
slope versus dZ, curvature < 15
  n = 32344 
  X=0, Y = 62.72 +/- 4.69 
  Weighted least-squares fit:  Y = 66.3 + -0.030 X  + 0.00170 X**2 

curvature versus dZ, slope < 10
  n = 25064 
  X=0, Y = 65.28 +/- 8.73 
  Weighted least-squares fit:  Y = 65.0 + 0.776 X  + -0.07830 X**2 


Number of samples 119245
Max dz = 900
Mean dz = 97
RMS dz = 129.965380006
100cm = 64.920122437 percentile value of dz