Frequencies for first 10,000 rows of oncall variable in nhamcsed2007 dataset :

    on call |
  attending |
physician/f |
ellow/resid |
   ent seen |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,592       95.92       95.92
        yes |        408        4.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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