For those that are interested, I kept logs and processed them. The experience needed per level appears to increase linearly. For the shoulders, I killed only snakes in SL (dark blue to level 100). It took 37 solo kills for level 1 to level 2 and increased between 5 and 6 kills per level after. Here is a chart if you want to know how far you are. Halfway was almost 15% into level 13.
Here is a chart:
Level 1 to 2, kills = 37, Total = 37, 2%
Level 2 to 3, kills = 43, Total = 80, 5%
Level 3 to 4, kills = 48, Total = 128, 8%
Level 4 to 5, kills = 53, Total = 181, 11%
Level 5 to 6, kills = 59, Total = 240, 15%
Level 6 to 7, kills = 65, Total = 305, 19%
Level 7 to 8, kills = 70, Total = 375, 23%
Level 8 to 9, kills = 76, Total = 451, 27%
Level 9 to 10, kills = 81, Total = 532, 32%
Level 10 to 11, kills = 87, Total = 619, 38%
Level 11 to 12, kills = 92, Total = 711, 43%
Level 12 to 13, kills = 98, Total = 809, 49%
Level 13 to 14, kills = 103, Total = 912, 55%
Level 14 to 15, kills = 109, Total = 1021, 62%
Level 15 to 16, kills = 114, Total = 1135, 69%
Level 16 to 17, kills = 120, Total = 1255, 76%
Level 17 to 18, kills = 126, Total = 1381, 84%
Level 18 to 19, kills = 131, Total = 1512, 92%
Level 19 to 20, kills = 136, Total = 1648, 100%
I know at least other equipment also scales, but don't know if the above % matches. I had heard people claim that the VoA range tear halfway point is about level 13, so this may map. I know that the tear scales in some way.
