Frequencies for first 10,000 rows of alcosyn variable in natl1996 dataset :

      Fetal |
    Alcohol |
   Syndrome |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |      9,905       99.05       99.06
          9 |         94        0.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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