Frequencies for first 10,000 rows of vmonth variable in nhamcsed2015 dataset :

   Month of |
      Visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |        702        7.02        7.02
   February |        660        6.60       13.62
      March |        940        9.40       23.02
      April |        564        5.64       28.66
        May |        931        9.31       37.97
       June |        809        8.09       46.06
       July |        798        7.98       54.04
     August |        866        8.66       62.70
  September |        828        8.28       70.98
    October |        828        8.28       79.26
   November |      1,238       12.38       91.64
   December |        836        8.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017