Salaries are meant to be higher as inflation increases, I’m not sure how exactly the government looks at it. However, I’m not sure of the possibility that you do a job today and then tomorrow, you get paid lower. Especially the fact you said 5 years ago. What is your colleague’s job description? Aren’t they getting better at the job too? Because with 5 years you should be better, and without considering inflation, being better would usually amount to getting paid higher.