Frequencies for first 10,000 rows of retprn variable in nhamcsopd1994 dataset :

  return if |
    needed, |
     p.r.n. |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,001       80.01       80.01
          1 |      1,999       19.99      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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