Frequencies for first 10,000 rows of uca_ompha variable in natlterr2005 dataset :

Omphalocele |
/Gastroschi |
    sis U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          2        0.02        0.02
          2 |      8,246       82.46       82.48
          9 |      1,752       17.52      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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