Frequencies for first 10,000 rows of refothph variable in nhamcsopd1999 dataset :

referred to |
      other |
physician/c |
      linic |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,066       90.66       90.66
          1 |        934        9.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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