Frequencies for first 10,000 rows of vmonth variable in nhamcsopd2011 dataset :

   Month of |
      Visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |      1,336       13.36       13.36
   February |        969        9.69       23.05
      March |        935        9.35       32.40
      April |        548        5.48       37.88
        May |        446        4.46       42.34
       June |      1,011       10.11       52.45
       July |        997        9.97       62.42
     August |        738        7.38       69.80
  September |        833        8.33       78.13
    October |        693        6.93       85.06
   November |        774        7.74       92.80
   December |        720        7.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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