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

Infertility |
  Treatment |
 Used Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,777       97.77       97.77
          U |        128        1.28       99.05
          Y |         95        0.95      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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