Frequencies for first 10,000 rows of retprn variable in nhamcsed2001 dataset :

  return if |
    needed, |
p.r.n./appt |
          . |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,059       60.59       60.59
          1 |      3,941       39.41      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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