Frequencies for first 10,000 rows of vmonth variable in nhamcsed2006 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    january |      1,118       11.18       11.18
   february |        864        8.64       19.82
      march |        536        5.36       25.18
      april |        605        6.05       31.23
        may |        867        8.67       39.90
       june |        870        8.70       48.60
       july |        761        7.61       56.21
     august |        718        7.18       63.39
  september |      1,078       10.78       74.17
    october |        940        9.40       83.57
   november |        945        9.45       93.02
   december |        698        6.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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