[Greece Greek Pharmacist Drugs]REUTERS/John Kolesidis We hear it all the time: "I should be making more." It's easy to dismiss this as nothing more than the grumblings of a frustrated worker, but according to new salary data from Glassdoor, there's much more truth behind this complaint than you might imagine. According to information from our Know Your Worth™ personalized salary estimator, the average U.S. employee could be earning $7,528, or 13.3% more per year than his or her current annual base salary. As if that wasn't surprising enough, some people in specific roles are missing out on even more money. If you are in one of these 25 underpaid positions, don't get angry — get paid fairly! Nothing shows confidence quite like applying for a new, higher-paying job or renegotiating your current salary. Whichever you choose to do, here's all the information you need to know your worth! 10. COMMUNICATIONS MANAGER Flickr/Sebastiaan ter Burg POTENTIAL SALARY GROWTH: 14.8% or $13,334 CURRENT MEDIAN BASE SALARY: $76,498 CURRENT MARKET VALUE: $89,831 9. MARKETING MANAGER Strelka Institute for Media, Architecture and Design/Flickr POTENTIAL SALARY GROWTH: 15.1% or $5,320 CURRENT MEDIAN BASE SALARY: $30,000 CURRENT MARKET VALUE: $35,320 8. MEDICAL ASSISTANT Getty Images/Christopher Furlong POTENTIAL SALARY GROWTH: 15.1% or $5,320 CURRENT MEDIAN BASE SALARY: $30,000 CURRENT MARKET VALUE: $35,320 SEE THE REST OF THE STORY AT BUSINESS INSIDER