Frequencies for modvers variable in icd2cchcc12xw2007 dataset :

      Model |
    Version |      Freq.     Percent        Cum.
------------+-----------------------------------
         12 |      3,183      100.00      100.00
------------+-----------------------------------
      Total |      3,183      100.00

by Jean Roth , jroth@nber.org , 12 Jan 2016