Frequencies for first 10,000 rows of senbefl variable in nhamcsopd2007 dataset :

seen before |
   imputed? |      Freq.     Percent        Cum.
------------+-----------------------------------
not imputed |      9,624       96.24       96.24
    imputed |        376        3.76      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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