Frequencies for first 10,000 rows of retprn variable in nhamcsed2010 dataset :

  Return if |
     needed |
PRN/appoint |
       ment |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      6,593       65.93       65.93
        yes |      3,407       34.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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