Frequencies for first 10,000 rows of intrn_rsdnt_srvc_cd variable in pos2005 dataset :

       srv: |
interns and |
  residents |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,314       83.14       83.14
          0 |      1,656       16.56       99.70
          1 |          6        0.06       99.76
          2 |         20        0.20       99.96
          3 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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