Frequencies for first 10,000 rows of vmonth variable in nhamcsed2004 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    january |        341        3.41        3.41
   february |        816        8.16       11.57
      march |        813        8.13       19.70
      april |        900        9.00       28.70
        may |        993        9.93       38.63
       june |        937        9.37       48.00
       july |        657        6.57       54.57
     august |        698        6.98       61.55
  september |      1,167       11.67       73.22
    october |        855        8.55       81.77
   november |      1,100       11.00       92.77
   december |        723        7.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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