Frequencies for first 10,000 rows of urf_rh variable in natl2004 dataset :

         Rh |
sensitizati |
       on U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         37        0.37        0.37
          2 |      8,982       89.82       90.19
          9 |        981        9.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 21 Jan 2016