Frequencies for first 10,000 rows of unkins variable in namcs1996 dataset :

    unknown |
  insurance |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,567       95.67       95.67
          1 |        433        4.33      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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