Those of you in my IS210 class may find the Polity IV data to be of use when writing your paper. Click on the image below to take you to the website, where (if you scroll down to the bottom) you can see the regime scores (between -10 and +10) for each country over many years. See the example at the bottom of this post.
Here’s an exampe of the history of movements in regime for El Salvador from 1946 until 2010. How many changes in regime does El Salvador seem to have experienced in the post-WWII period? What happened in the early 1980s?