Frequencies for first 10,000 rows of vworkrel variable in nhamcsed2005 dataset :

   is visit |
       work |
   related? |      Freq.     Percent        Cum.
------------+-----------------------------------
      blank |        432        4.32        4.32
        yes |        255        2.55        6.87
         no |      8,919       89.19       96.06
    unknown |        394        3.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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