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.