Frequencies for first 10,000 rows of renalage variable in natl1990 dataset :

      Renal |
   agenesis |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          2        0.02        0.02
          2 |      9,936       99.36       99.38
          9 |         62        0.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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