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

Were procedures provided at this visit? |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                                     No |      5,080       50.80       50.80
                                    Yes |      4,772       47.72       98.52
Entire item blank, including 'None' box |        148        1.48      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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