Frequencies for first 10,000 rows of proc variable in nhamcsed2011 dataset :

  Were procedures |
 provided at this |
           visit? |      Freq.     Percent        Cum.
------------------+-----------------------------------
               No |      4,982       49.82       49.82
              Yes |      4,480       44.80       94.62
Entire item blank |        538        5.38      100.00
------------------+-----------------------------------
            Total |     10,000      100.00

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