Experience Table

The formula for level gain is:
Next Level Experience = Previous Level Experience + (Previous Level * 1000)
In other words:
Level 1 -> 0
Level 2 -> 1000
Level 3 -> 3000
Level 4 -> 6000
Level 5 -> 10000
Level 6 -> 15000
Level 7 -> 21000
Level 8 -> 28000
Level 9 -> 36000
Level 10 -> 45000

etc...