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

    roadway |
      grade |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         75        0.75        0.75
          1 |      5,749       57.49       58.24
          2 |        179        1.79       60.03
          3 |         97        0.97       61.00
          4 |         32        0.32       61.32
          5 |        739        7.39       68.71
          6 |        948        9.48       78.19
          8 |      1,983       19.83       98.02
          9 |        198        1.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016