Frequencies for first 10,000 rows of prov1925 variable in pos1991 dataset :

        210 |
   syphilis |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,536       85.36       85.36
          N |        886        8.86       94.22
          Y |        578        5.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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