Frequencies for first 10,000 rows of vmonth variable in nhamcsed2005 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    january |        854        8.54        8.54
   february |        826        8.26       16.80
      march |        978        9.78       26.58
      april |        974        9.74       36.32
        may |      1,063       10.63       46.95
       june |        931        9.31       56.26
       july |        900        9.00       65.26
     august |        568        5.68       70.94
  september |        399        3.99       74.93
    october |        829        8.29       83.22
   november |        713        7.13       90.35
   december |        965        9.65      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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