Frequencies for first 10,000 rows of intrn_rsdnt_srvc_cd variable in pos2009 dataset :

       SRV: |
INTERNS AND |
  RESIDENTS |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,205       82.05       82.05
          0 |      1,764       17.64       99.69
          1 |          7        0.07       99.76
          2 |         23        0.23       99.99
          3 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017