Frequencies for first 10,000 rows of prov1945 variable in pos1993 dataset :

        320 |
 urinalysis |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,797       87.97       87.97
          N |        513        5.13       93.10
          Y |        690        6.90      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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