Under normal condition, there should be a merit increase (5%) every year. If the range is 30%, you need 6 years to reach the top. I guess your co-workers have already topped out while you are still in the middle of the range (as you were employed later). This should have nothing to do with experience, work responsibility, and age. you could have started at the top if you negociated very hard and you had previous employment history with a much higher pay. Since you have been employed for quite some time, it is pretty hard to increase your salary unless your boss can create a different position.