Question:

Why does the document count in the Vault library show as "1-25 of about xxxx"?

Answer:

The Vault library's document count is only an estimate of the number of documents in the Vault. In large Vaults with many documents and users, many changes can occur at any time(documents being created or deleted).  This can cause the library document count to become temporarily out of sync, until the document count is updated. 

The library document count is just an estimate and should not be relied upon if users need an accurate count of all documents in Vault. If an accurate document count is needed, users should instead check the General settings page (Admin -> About -> Vault Information page).

This count on the settings page is updated every time this page is accessed, so it will always be up to date and provide the accurate document count.

Related Documentation:

Vault Help Documentation: N/A