Frequencies for first 10,000 rows of prov2525 variable in pos1991 dataset :

      spec: |
   thoracic |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,683       96.83       96.83
          N |        297        2.97       99.80
          Y |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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