The Live Data table in XWik.XWikiClasses (Data types page) shows an incorrect number of pages

The share Page Application (15.10.4) creates four (4) pages upon installation, but Page Count reports six (6). Six is the total number of XWiki.Mail objects held by the four (4) pages.
As an example, described in the XWiki forum:
https://forum.xwiki.org/t/accessing-any-class-properties-with-livedata-macro/13781/8?u=ricardo_rodriguez
The same is true for other classes: in our installation, XWiki.XWikiGlobalRights show forty-six (46) pages. There are thirty-eight (38) pages but forty-six (46) instances of XWiki.XWikiGlobalRights type. I don't know if it affects every Live Data table showing the number of pages holding an object of a given class.

Reproduction steps

1. Go to http://localhost:8080/xwiki/bin/view/XWiki/XWikiClasses
2. Search for a row containing a class where several XObject are stored in the same page (e.g., XWiki.Mail)
3. Check the "page count"

Expected

The actual number of pages with at least one XObject is displayed (i.e., 4 in a standard distrib)

Actual

The total number of XObjects is displayed (i.e., 6 in a standard distrib)