Frequencies for first 10,000 rows of vmonth variable in nhamcsopd2004 dataset :

   month of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
    january |        915        9.15        9.15
   february |        700        7.00       16.15
      march |        867        8.67       24.82
      april |        441        4.41       29.23
        may |        467        4.67       33.90
       june |      1,307       13.07       46.97
       july |        926        9.26       56.23
     august |        208        2.08       58.31
  september |        841        8.41       66.72
    october |        676        6.76       73.48
   november |      1,852       18.52       92.00
   december |        800        8.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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