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

    MEDICAL |
     SCHOOL |
AFFILIATION |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,649       86.49       86.49
          1 |         74        0.74       87.23
          2 |        121        1.21       88.44
          3 |         34        0.34       88.78
          4 |      1,122       11.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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