Frequencies for first 10,000 rows of ectoe variable in namcs2007 dataset :

  practice has |
      computer |
    system for |
    orders for |
        tests? |      Freq.     Percent        Cum.
---------------+-----------------------------------
         blank |         35        0.35        0.35
       unknown |         52        0.52        0.87
           yes |      3,356       33.56       34.43
            no |      6,487       64.87       99.30
    turned off |         70        0.70      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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