Frequencies for first 10,000 rows of vmonth variable in nhamcsed2013 dataset :

   Month of |
      Visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |        955        9.55        9.55
   February |        674        6.74       16.29
      March |        654        6.54       22.83
      April |        885        8.85       31.68
        May |      1,144       11.44       43.12
       June |        875        8.75       51.87
       July |      1,114       11.14       63.01
     August |        581        5.81       68.82
  September |        513        5.13       73.95
    October |        591        5.91       79.86
   November |      1,187       11.87       91.73
   December |        827        8.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016