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

      does emr |
system include |
       imaging |
      results? |      Freq.     Percent        Cum.
---------------+-----------------------------------
           Yes |      3,291       32.91       32.91
            No |        763        7.63       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