Frequencies for first 10,000 rows of eimgres variable in namcs2009 dataset :

  practice has |
  computerized |
    system for |
       viewing |
       imaging |
      results? |      Freq.     Percent        Cum.
---------------+-----------------------------------
         blank |         37        0.37        0.37
       unknown |         13        0.13        0.50
           yes |      4,701       47.01       47.51
            no |      5,113       51.13       98.64
    turned off |        136        1.36      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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