Frequencies for first 10,000 rows of epnoteso variable in nhamcsopd2006 dataset :

      does emr |
system include |
      clinical |
        notes? |      Freq.     Percent        Cum.
---------------+-----------------------------------
           Yes |      2,658       26.58       26.58
            No |      1,396       13.96       40.54
       Unknown |        153        1.53       42.07
Not applicable |      5,529       55.29       97.36
         Blank |        264        2.64      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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