Frequencies for month variable in vehicle dataset :

      month |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         51       10.81       10.81
          2 |         45        9.53       20.34
          3 |         51       10.81       31.14
          4 |         35        7.42       38.56
          5 |         43        9.11       47.67
          6 |         49       10.38       58.05
          7 |         23        4.87       62.92
          8 |         39        8.26       71.19
          9 |         33        6.99       78.18
         10 |         39        8.26       86.44
         11 |         33        6.99       93.43
         12 |         31        6.57      100.00
------------+-----------------------------------
      Total |        472      100.00

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