Frequencies for first 10,000 rows of vmonth variable in nhamcsed1993 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |        926        9.26        9.26
   February |        897        8.97       18.23
      March |        835        8.35       26.58
      April |        805        8.05       34.63
        May |      1,002       10.02       44.65
       June |        777        7.77       52.42
       July |        852        8.52       60.94
     August |        750        7.50       68.44
  September |        770        7.70       76.14
    October |        877        8.77       84.91
   November |        636        6.36       91.27
   December |        873        8.73      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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