Frequencies for first 10,000 rows of lumbar variable in nhamcsed2015 dataset :

     Lumbar |
   puncture |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,970       99.70       99.70
        Yes |         30        0.30      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017