Frequencies for first 10,000 rows of ca_omph variable in natlterr2010 dataset :

Omphalocele |
        RFP |
639=f_ca_om |
      pha R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      4,656       46.56       46.56
          N |      4,364       43.64       90.20
          U |        973        9.73       99.93
          Y |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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