When giving the player large amounts of XP via the /xp add command, inconsistent results are obtained when querying the player's xp afterwards, depending on whether the XP was added all at once or in multiple steps.

How to reproduce:

1. Give the player 16,000,000 experience points with /xp add Player 16000000 points
2. Query the player's experience points with /xp query Player points
3. Minecraft returns the result: "Player has 10668 experience points"
4. Reset the player's XP
5. Give the player 8,000,000 experience points with /xp add Player 8000000 points
6. Repeat step 5 once
7. Query the player's experience points with /xp query Player points

Expected outcome: Minecraft returns the result: "Player has 10668 experience points"

Actual outcome: Minecraft returns the result: "Player has 10686 experience points"

Neither of these results are correct - 16 million points should be equivalent to 1903 levels + 10677 points. Similar inconsistencies occur when dealing with experience amounts around this ballpark or higher.