Frequencies for first 10,000 rows of refothmd variable in nhamcsopd2001 dataset :

   refer to |
   other md |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,026       90.26       90.26
          1 |        974        9.74      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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