You can give only a property (let's say P31) and it gives you the four most used values + analyze of sources and quality in overall (check this out)

 and then you can see about ~33% of them are sources which 29.1% of them are based on Wikipedia.

You can give a property and multiple values you want. Let's say you want to compare P27:Q183 (Country of citizenship: Germany) and P27:Q30 (US)

Check this out. And you can see US biographies are more abundant (300K over 200K) but German biographies are more descriptive (3.8 description per item over 3.2 description over item)

One important note: Compare P31:Q5 (a trivial statement) 46% of them are not sourced at all and 49% of them are based on Wikipedia *but* get this statistics for population properties (P1082) It's not a trivial statement and we need to be careful about them. It turns out there are slightly more than one reference per statement and only 4% of them are based on Wikipedia. So we can relax and enjoy these highly-sourced data.

Requests:

• Please tell me whether do you want this tool at all
  
• Please suggest more ways to analyze and catch unsourced materials

Future plan (if you agree to keep using this tool):

• Support more datatypes (e.g. date of birth based on year, coordinates)
• Sitelink-based and reference-based analysis (to check how much of articles of, let's say, Chinese Wikipedia are unsourced)

• Free-style analysis: There is a database for this tool that can be used for way more applications. You can get the most unsourced statements of P31 and then you can go to fix them. I'm trying to build a playground for this kind of tasks)

I hope you like this and rock on!

Best