Frequencies for first 10,000 rows of vmonth variable in nhamcsed2008 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    january |        506        5.06        5.06
   february |        892        8.92       13.98
      march |        973        9.73       23.71
      april |        760        7.60       31.31
        may |        840        8.40       39.71
       june |      1,025       10.25       49.96
       july |        800        8.00       57.96
     august |        905        9.05       67.01
  september |      1,186       11.86       78.87
    october |        588        5.88       84.75
   november |        677        6.77       91.52
   december |        848        8.48      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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