Frequencies for first 10,000 rows of month variable in vehicle dataset :

      month |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        697        6.97        6.97
          2 |        605        6.05       13.02
          3 |        840        8.40       21.42
          4 |        736        7.36       28.78
          5 |        732        7.32       36.10
          6 |        913        9.13       45.23
          7 |        854        8.54       53.77
          8 |      1,007       10.07       63.84
          9 |        947        9.47       73.31
         10 |        946        9.46       82.77
         11 |        888        8.88       91.65
         12 |        835        8.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016