Frequencies for first 10,000 rows of therprev variable in namcs1997 dataset :

       were |
  ther/prev |
   services |
ordered/pro |
     vided? |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      5,894       58.94       58.94
        Yes |      4,091       40.91       99.85
  No answer |         15        0.15      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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