Frequencies for first 10,000 rows of ip_hepatc variable in natl2014 dataset :

Hepatitis C |
      Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,767       97.67       97.67
          U |        169        1.69       99.36
          Y |         64        0.64      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016