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

Diaphragmat |
  ic hernia |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         36        0.36        0.36
          2 |      9,691       96.91       97.27
          9 |        273        2.73      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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