Frequencies for first 10,000 rows of none variable in nhamcsed1996 dataset :

       does |
patient now |
have - none |
  of above? |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        403        4.03        4.03
          1 |      9,597       95.97      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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