Frequencies for first 10,000 rows of vmonth variable in nhamcsed1992 dataset :

   Month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |        794        7.94        7.94
   February |        920        9.20       17.14
      March |      1,113       11.13       28.27
      April |      1,180       11.80       40.07
        May |        851        8.51       48.58
       June |        485        4.85       53.43
       July |        837        8.37       61.80
     August |        622        6.22       68.02
  September |        488        4.88       72.90
    October |        634        6.34       79.24
   November |        630        6.30       85.54
   December |      1,446       14.46      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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