Frequencies for first 10,000 rows of ume_primc variable in natl2007 dataset :

    Primary |
  C-Section |
        RFP |
732=f_u_pri |
       mc U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,552       15.52       15.52
          2 |      8,389       83.89       99.41
          9 |         59        0.59      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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