Frequencies for first 10,000 rows of prov1935 variable in pos1991 dataset :

        300 |
  chemistry |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,536       85.36       85.36
          N |        705        7.05       92.41
          Y |        759        7.59      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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