Frequencies for first 10,000 rows of alcosyn variable in natl1994 dataset :

      Fetal |
    Alcohol |
   Syndrome |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          2 |      9,943       99.43       99.44
          9 |         56        0.56      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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