Frequencies for first 10,000 rows of pastfl variable in nhamcsopd2008 dataset :

  number of |
past visits |
   imputed? |      Freq.     Percent        Cum.
------------+-----------------------------------
not imputed |      8,647       86.47       86.47
    imputed |      1,353       13.53      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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