How do you measure that? As others said, itʼs a somewhat impossible task.
You canʼt really measure skill, for one thing. The fact you write a piece of software in two days and i write the same in three wonʼt make you better; speed is one factor, but there is also quality, maintainability, and so on.
You also canʼt measure it purely by salary. A $21000 yearly salary might be low in one country, and a pretty good one elsewhere.
What you should aim for is not being in the top 5% but becoming better than yesterday yourself every single day.