I selected a single file, and looked at the project statistics. Selected is one number, and the count at the bottom of the editor is a different (but close) number. Then, I looked at Project - Text - Statistics. It matches the numbers at the bottom of the editor.
Project - Selected: words = 1633, characters = 8893
Editor bar: words - 1631, characters = 8866
Project - Text statistics: words = 1631, characters 8866
Not sure why the Selected document is coming up with different count, though.