Frequencies for first 10,000 rows of ip_hepatc variable in natl2015 dataset :

Hepatitis C |
      Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,800       98.00       98.00
          U |        128        1.28       99.28
          Y |         72        0.72      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016