Annual pay is generally determined by the following 9 factors factors:
1. Educational attainment
2. Chosen profession
3. Years of experience
4. Hours worked
5. Work ethic
6. Social skills
7. Competency and proficiency
8. Ability to cooperate with, inspire and lead your co-workers
9. Ambition to rise in the organization.
So, if you want to earn more, you must stay in school longer, learn a financially marketable skill and make yourself indispensable.