Frequencies for length variable in form2007 dataset :

     Format |
     length |      Freq.     Percent        Cum.
------------+-----------------------------------
          3 |          2        0.05        0.05
          7 |          9        0.21        0.26
          8 |          3        0.07        0.33
          9 |         13        0.31        0.64
         10 |          4        0.10        0.74
         11 |          8        0.19        0.93
         12 |         22        0.52        1.45
         13 |         60        1.43        2.88
         14 |         75        1.78        4.66
         15 |        141        3.36        8.02
         16 |      1,338       31.84       39.86
         17 |        167        3.97       43.84
         18 |         35        0.83       44.67
         20 |         35        0.83       45.50
         21 |         20        0.48       45.98
         22 |        283        6.73       52.71
         23 |         31        0.74       53.45
         24 |         37        0.88       54.33
         26 |         12        0.29       54.62
         28 |         91        2.17       56.78
         35 |      1,425       33.91       90.69
         39 |          9        0.21       90.91
         40 |        367        8.73       99.64
         41 |         15        0.36      100.00
------------+-----------------------------------
      Total |      4,202      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016