Frequencies for first 10,000 rows of vmonth variable in nhamcsed2009 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        727        7.27        7.27
          2 |        808        8.08       15.35
          3 |      1,093       10.93       26.28
          4 |        765        7.65       33.93
          5 |        951        9.51       43.44
          6 |        745        7.45       50.89
          7 |        671        6.71       57.60
          8 |        453        4.53       62.13
          9 |        839        8.39       70.52
         10 |      1,450       14.50       85.02
         11 |      1,061       10.61       95.63
         12 |        437        4.37      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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