What type of salary raises can a computer programmer expect in their career?

Salary raises in any field are directly linked to the perceived benefit to the employer. If a programmer is not GOOD for the company, why would the company want to offer incentives for the programmer to stay around? On the other hand if a programmer, or for that matter any employee, is a benefit to the company he or she can expect significant raises through his/her career. Companies do not want to have the good people leave.