I have found that to be the case as well. Using a combination of skillful salary negotiation, leveraging counteroffers (use sparingly), and hopping between companies, I have averaged 19.5% yearly salary increases for the past 10 years. Obviously this is not sustainable, since my current salary level limits the number of positions I can take without taking a pay cut.

For those who are curious, it took 6 companies over those 10 years, with 1 career change from teacher/manager to programmer. During that time, the largest year to year jump was 38% (2nd was 37%), the longest time spent at a company was 3 years, the shortest was 3 months. I used the counteroffer trick twice, once quitting and once staying.