Frequencies for first 10,000 rows of prov2020 variable in pos1994 dataset :

        900 |
cytogenetic |
          s |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,798       87.98       87.98
          N |      1,187       11.87       99.85
          Y |         15        0.15      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017