Frequencies for first 10,000 rows of uca_spina variable in natl2008 dataset :

      Spina |
bifida/Meni |
ngocele RFP |
753=f_uca_s |
   pina U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          3        0.03        0.03
          2 |      9,994       99.94       99.97
          9 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 May 2016