Frequencies for first 10,000 rows of hyaline variable in natlterr2002 dataset :

    Hyaline |
   membrane |
    disease |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         20        0.20        0.20
          2 |      9,964       99.64       99.84
          8 |         14        0.14       99.98
          9 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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