United Nations UPR may be an useful source of information. What I would suggest, also, is to consult some reports from well-known NGOs. Here is the online version of the World Report of Human Rights Watch where you can perform research in the database looking for each single Country. It includes obviously cases of violations of main international instruments on HR.
You may already have thought about this and it may or may not have significance depending on your project, but many of these statistics are based on "self-report", meaning that nations police themselves, decide what the written parameters mean, and send information (or don't) that consider either relevant, or politically wise, or both. Good luck!