With the release of Phase 3 (Patch 3.4.2) Expertise was changed to continuous rather than the previous truncated amount every 0.25%. AMR does not appear to be treating Expertise in accordance to this change from what I can tell.
In the Patch Notes for 3.4.2 it states: “Fixed a display issue causing the expertise rating calculations to round up or down to the nearest quarter of a percent on the character sheet.” Link: Wrath Classic Patch Notes Version 3.4.2 - Wrath of the Lich King Classic Discussion - World of Warcraft Forums
After the patch went live it was tested and found to match what is described above. Proof is available here: [BUG] Expertise rating is still truncated · Issue #556 · JamminL/wotlk-classic-bugs · GitHub