Frequencies for first 10,000 rows of vmonth variable in nhamcsed2001 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |        935        9.35        9.35
   February |        812        8.12       17.47
      March |        991        9.91       27.38
      April |      1,046       10.46       37.84
        May |        667        6.67       44.51
       June |        586        5.86       50.37
       July |        820        8.20       58.57
     August |        698        6.98       65.55
  September |        812        8.12       73.67
    October |      1,039       10.39       84.06
   November |        792        7.92       91.98
   December |        802        8.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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