|  Age group | 
   Meannumber  | 
   ObservedLength(mm) | 
   Back calculated lengths in mm 
     1   2 3   4 5 6 | 
   
   
  |  I | 
   34 | 
  11.0 | 
  10.46 | 
   
   
  |    II | 
   41 | 
   15.5 | 
  10.69 14.15 | 
   
   
  |   III | 
   61 | 
   18.9 | 
  11.50 15.20 17.68 | 
   
   
  |  I V | 
   36 | 
   21.7 | 
  11.35 15.37 16.98 20.19 | 
   
   
  |   V | 
   33 | 
  23.9 | 
  10.81 15.85 18.81 20.90 23.44  | 
   
   
  |  VI | 
   12 | 
   26.4 | 
  10.75 15.34 19.52 22.02 23.69 25.36 | 
   
   
  | Average total | 
   217 | 
    | 
  10.92 15.18 18.95 21.44 23.57 25.36 | 
   
   
  | Increment of length | 
    | 
    | 
  10.92 4.26 3.77 2.49 2.13 1.79 | 
   
   
  | % of annual Increment | 
    | 
    | 
  43.1 16.88 14.87 9.82 8.40 7.06 |