Frequencies for first 10,000 rows of uca_circ variable in natl2006 dataset :

      Other |
Circulatory |
/Respirator |
y Anomalies |
        RFP |
758=f_uca_c |
    ircul U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          2        0.02        0.02
          2 |      9,850       98.50       98.52
          9 |        148        1.48      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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