Frequencies for first 10,000 rows of eimgreso variable in nhamcsopd2009 dataset :

 does opd have |
  computerized |
    system for |
    viewing of |
       imaging |
      results? |      Freq.     Percent        Cum.
---------------+-----------------------------------
         blank |        518        5.18        5.18
       unknown |        431        4.31        9.49
           yes |      7,298       72.98       82.47
            no |      1,753       17.53      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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