Frequencies for first 10,000 rows of vmonth variable in namcs2001 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    January |      1,080       10.80       10.80
   February |      1,047       10.47       21.27
      March |        918        9.18       30.45
      April |        856        8.56       39.01
        May |        782        7.82       46.83
       June |        837        8.37       55.20
       July |        840        8.40       63.60
     August |        794        7.94       71.54
  September |        671        6.71       78.25
    October |      1,028       10.28       88.53
   November |        728        7.28       95.81
   December |        419        4.19      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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