Concordance results for frequency and groups?

I have a database with 714 documents all within one group. When I use the Concordance tool and search on a particular word, in this case “devil”, the Concordance gives me a frequency number of 696 and a Groups number of 165. I am assuming that the Groups number is the same number of files of my 714 in which the word appears?

However, when I double click on the word and then count the number of files which appear in the side window, there are only 50. This makes me think the word appears in only 50 files instead of 165.

If the Groups number does not reflect the number of files in which the word appears, then what does the number mean? And, then, how do I get a count of the number of files in which the word appears without having to do a manual count?