Frequencies for first 10,000 rows of proc variable in nhamcsed2001 dataset :

   were any |
 procedures |
provided at |
this visit? |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      5,221       52.21       52.21
        Yes |      4,178       41.78       93.99
  No answer |        601        6.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016