Frequencies for month variable in vehicle dataset :

      month |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         56        8.95        8.95
          2 |         53        8.47       17.41
          3 |         51        8.15       25.56
          4 |         41        6.55       32.11
          5 |         44        7.03       39.14
          6 |         60        9.58       48.72
          7 |         59        9.42       58.15
          8 |         60        9.58       67.73
          9 |         40        6.39       74.12
         10 |         67       10.70       84.82
         11 |         39        6.23       91.05
         12 |         56        8.95      100.00
------------+-----------------------------------
      Total |        626      100.00

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