Frequencies for first 10,000 rows of pastfl variable in nhamcsopd2004 dataset :

   was past |
      visit |
   imputed? |      Freq.     Percent        Cum.
------------+-----------------------------------
not imputed |      9,378       93.78       93.78
    imputed |        622        6.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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