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

   Month of |
      Visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |        855        8.55        8.55
   February |        678        6.78       15.33
      March |        705        7.05       22.38
      April |        892        8.92       31.30
        May |        632        6.32       37.62
       June |        946        9.46       47.08
       July |      1,252       12.52       59.60
     August |        993        9.93       69.53
  September |        982        9.82       79.35
    October |        589        5.89       85.24
   November |      1,033       10.33       95.57
   December |        443        4.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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