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

    Uterine |
 bleeding U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         32        0.32        0.32
          2 |      8,987       89.87       90.19
          9 |        981        9.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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