Frequencies for first 10,000 rows of noopteff variable in nhamcsed2008 dataset :

  does your |
ed use none |
     of the |
     above? |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,068       90.68       90.68
        yes |        932        9.32      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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