Concordance of proper names in a folder

Good morning Devonafficionados. I want to find the most frequently occurring mentions of named people in a folder of openoffice, word and pdf files. The folder can be imported as a database, so it would be fine to simply make a ranked list of proper names in a Devonthink 3 database. A less desireable alternative could be to make a ranked list of capitalized words and I could manually eyeball the list. I am assuming it is difficult to exclude place names. Is there a way to find use e.g. the concordance function? I’m happy for any suggestions and thanks in advance.

E.g. you could import the folder, then select the group in the database and Tools > Inspectors > Concordance > List will show you a list of all words which can be sorted in various ways. In addition, via the contextual menu it’s also possible to exclude words from the concordance.

I don’t think the index is case-sensitive, is it?
If it was, perhaps it would be possible to sort by capitalization to group proper names of people, organizations, companies, etc.