Frequencies for first 10,000 rows of proc variable in nhamcsed2009 dataset :

       were |
 procedures |
provided at |
this visit? |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,315       53.15       53.15
          1 |      4,309       43.09       96.24
          2 |        376        3.76      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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