Frequencies for first 10,000 rows of renalage variable in natlterr2001 dataset :

      Renal |
   agenesis |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |      9,973       99.73       99.74
          8 |         20        0.20       99.94
          9 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015