Frequencies for first 10,000 rows of clubfoot variable in linkco1991us_num dataset :

  Club foot |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         34        0.34        0.34
          2 |      9,693       96.93       97.27
          9 |        273        2.73      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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