Frequencies for first 10,000 rows of pastfl variable in nhamcsopd2006 dataset :

  number of |
past visits |
   imputed? |      Freq.     Percent        Cum.
------------+-----------------------------------
Not imputed |      9,106       91.06       91.06
    Imputed |        894        8.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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