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

    medical |
     school |
affiliation |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,693       86.93       86.93
          1 |         73        0.73       87.66
          2 |        112        1.12       88.78
          3 |         38        0.38       89.16
          4 |      1,084       10.84      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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