Frequencies for first 10,000 rows of lumbar variable in nhamcsed2013 dataset :

     Lumbar |
   puncture |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,983       99.83       99.83
        Yes |         17        0.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016