The Xmas party is not the best place to lobby for a raise. so good thing you did not :) But assuming that figure is correct, you now have a simple fact to base your negotiation on. Plus inflation alone makes you worth more. Plus, keep a list of accomplishments and make them sound positively awesome without obvious embellishment. "But the ecoonemy we can't affords it." Get some stats that show them otherwise. "I will have to ask my boss about it." Absolutely I understand and I expect that you respect my work enough to lobby for a higher number for me". Go in there and get it! In my industry you talk raises once a year but I always made sure my boss knew what value I was adding and knew I expected more. If you can't get at least another $0.50 then that is also telling you something. Best of luck!
Don't worry, I have a little bit of common sense! Thank you for the advice. I'm not sure if I should mention about learning my coworkers' salaries, though. I can definitely produce the reasons that I should be earning more, but bringing them into it just sounds petty.