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

     Weight |
 Code-Truck |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         28        0.28        0.28
          1 |        751        7.51        7.79
          2 |        301        3.01       10.80
          4 |          7        0.07       10.87
          5 |         14        0.14       11.01
          6 |         41        0.41       11.42
          7 |          8        0.08       11.50
          8 |         19        0.19       11.69
          9 |      4,453       44.53       56.22
          . |      4,378       43.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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