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

      Spina |
bifida/Meni |
ngocele RFP |
753=f_uca_s |
   pina U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |      9,103       91.03       91.03
          9 |        897        8.97      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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