@Bálint These numbers don't take into account where those programmers are located in the USA.
It gets even crazier when it's world-wide.
I program in C++ mostly and make much less than this graph, however the average income in my region is $36,344 USD.
Average income in San Francisco: $104,879 USD and the cost of living follows accordingly.
So relative to the region I'm doing quite well but I'd have to triple my salary to maintain a relative income in San Francisco.
We'd need to have the numbers calculated first by normalizing the person's salary by the region's average income.