Frequencies for urgeo variable in impact2011 dataset :

      Large |
     Urban, |
Other Urban |
   or Rural |
Designation |
     of the |
  Providers |
 Geographic |
       CBSA |      Freq.     Percent        Cum.
------------+-----------------------------------
     LURBAN |      1,398       39.37       39.37
     OURBAN |      1,146       32.27       71.64
      RURAL |      1,007       28.36      100.00
------------+-----------------------------------
      Total |      3,551      100.00

by Jean Roth , jroth@nber.org , 16 Dec 2016