Frequencies for first 10,000 rows of vmonth variable in nhamcsed2007 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    january |        891        8.91        8.91
   february |        725        7.25       16.16
      march |      1,065       10.65       26.81
      april |        715        7.15       33.96
        may |        952        9.52       43.48
       june |        854        8.54       52.02
       july |        661        6.61       58.63
     august |        874        8.74       67.37
  september |      1,123       11.23       78.60
    october |        759        7.59       86.19
   november |        801        8.01       94.20
   december |        580        5.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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