Frequencies for first 10,000 rows of lumbar variable in nhamcsed2014 dataset :

     Lumbar |
   puncture |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,991       99.91       99.91
        Yes |          9        0.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017