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

      month |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        742        7.42        7.42
          2 |        672        6.72       14.14
          3 |        825        8.25       22.39
          4 |        812        8.12       30.51
          5 |        904        9.04       39.55
          6 |        809        8.09       47.64
          7 |        892        8.92       56.56
          8 |        929        9.29       65.85
          9 |        911        9.11       74.96
         10 |        878        8.78       83.74
         11 |        792        7.92       91.66
         12 |        834        8.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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