Frequencies for first 10,000 rows of none variable in nhamcsed1995 dataset :

       does |
patient now |
have - none |
  of above? |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        450        4.50        4.50
          1 |      9,550       95.50      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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