Hey! Please determine what property-value pair you want to see. If you want to get result for all values of your property, leave value part blank.
You can give only a property and it gives you the four most used values + analyze of sources and quality in overall (Run the query)
You also can give a property and multiple values you want. For example in case you want to compare P27:Q183 (Country of citizenship: Germany) and P27:Q30 (US) you should use "Q30|Q183".