Frequencies for first 10,000 rows of intrn_rsdnt_srvc_cd variable in pos2007 dataset :

       srv: |
interns and |
  residents |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,195       81.95       81.95
          0 |      1,775       17.75       99.70
          1 |          9        0.09       99.79
          2 |         19        0.19       99.98
          3 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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