Frequencies for first 10,000 rows of therprev variable in nhamcsopd1995 dataset :

       were |
  ther/prev |
   services |
ordered/pro |
     vided? |      Freq.     Percent        Cum.
------------+-----------------------------------
        Yes |      4,223       42.23       42.23
         No |      5,777       57.77      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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