Frequencies for first 10,000 rows of hyaline variable in natlterr1998 dataset :

    Hyaline |
   membrane |
    disease |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         25        0.25        0.25
          2 |      9,970       99.70       99.95
          9 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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