Frequencies for first 10,000 rows of retappt variable in nhamcsopd2010 dataset :

    return, |
      appt. |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      2,892       28.92       28.92
        yes |      7,108       71.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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