Frequencies for first 10,000 rows of senbefl variable in namcs2012 dataset :

        Was |
   variable |
   imputed: |
    patient |
    seen in |
   practice |
     before |      Freq.     Percent        Cum.
------------+-----------------------------------
Not imputed |      9,855       98.55       98.55
    Imputed |        145        1.45      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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