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

Hemoglobino |
      pathy |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          2        0.02        0.02
          2 |      9,951       99.51       99.53
          9 |         47        0.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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