Frequencies for first 10,000 rows of prov0645 variable in pos1991 dataset :

    medical |
     school |
affiliation |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,770       87.70       87.70
          1 |         71        0.71       88.41
          2 |        107        1.07       89.48
          3 |         42        0.42       89.90
          4 |      1,010       10.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016