Frequencies for first 10,000 rows of staffphy variable in nhamcsopd1994 dataset :

      staff |
  physician |
       seen |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      3,019       30.19       30.19
          1 |      6,981       69.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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