Frequencies for first 10,000 rows of hyaline variable in natl2001 dataset :

    Hyaline |
   membrane |
    disease |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        117        1.17        1.17
          2 |      9,880       98.80       99.97
          8 |          1        0.01       99.98
          9 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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