use http://econ.bc.edu/pol/polityiii.dta 

This dataset contains panel data, annual observations 1950-1994, for up to 162 countries.

Variables included (in addition to the alpha country name, 'cname', include:

Variable |     Obs        Mean   Std. Dev.       Min        Max
---------+-----------------------------------------------------
   ccode |    5748    451.9723   245.5979          2        950  
    year |    5748    1974.019   12.52112       1950       1994  
   democ |    5446    3.616599   4.292036          0         10  
 parcomp |    5446    2.519831   1.630931          0          5  
  xrcomp |    5446    1.691884   1.102046          0          3  
  xropen |    5446    3.313625   1.397119          0          4  
  xconst |    5446    3.786265   2.433739          1          7  
  

where the other measures include:

• "Democ"=overall or summary measure (democ score minus autoc score)
• "PARCOMP"=Competitiveness of political participation
• "XRCOMP"=Competitiveness of executive recruitment
• "XROPEN"=Openness of executive recruitment
• "XCONST"=Constraints on Chief Executive

Higher ratings on each of the scales are better, i.e. more democratic, more competitive, more open, etc.

For more information on these data, please contact Prof. David Deese, Political Science department.