Frequencies for first 10,000 rows of nochron variable in nhamcsed2009 dataset :

       does |
    patient |
 have: none |
     of the |
      above |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,227       12.27       12.27
          1 |      7,890       78.90       91.17
          2 |        883        8.83      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016