Frequencies for first 10,000 rows of urf_rh variable in natl2005 dataset :

         Rh |
sensitizati |
       on U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         76        0.76        0.76
          2 |      9,801       98.01       98.77
          9 |        123        1.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015