Frequencies for first 10,000 rows of prov1880 variable in pos1991 dataset :

        100 |
microbiolog |
          y |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,536       85.36       85.36
          N |      1,437       14.37       99.73
          Y |         27        0.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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