Frequencies for versionnum variable in busrules2015 dataset :

    Version |
     Number |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        189        1.87        1.87
          2 |        858        8.50       10.37
          3 |        913        9.04       19.42
          4 |      1,144       11.33       30.75
          5 |        885        8.77       39.51
          6 |        943        9.34       48.86
          7 |      1,591       15.76       64.62
          8 |      1,058       10.48       75.10
          9 |        535        5.30       80.40
         10 |        596        5.90       86.30
         11 |        397        3.93       90.23
         12 |        248        2.46       92.69
         13 |        101        1.00       93.69
         14 |        161        1.59       95.28
         15 |        106        1.05       96.33
         16 |         51        0.51       96.84
         17 |         25        0.25       97.09
         18 |         52        0.52       97.60
         19 |         75        0.74       98.35
         20 |        114        1.13       99.47
         21 |         53        0.53      100.00
------------+-----------------------------------
      Total |     10,095      100.00

by Jean Roth , jroth@nber.org , 9 Dec 2017