How did the han dynasty create a centralized government and complex bureaucracy in china?

By the end of the han period, china=130,000, bureaucrats=.2% of the population, wu ti established examinations for bureaucracy , and he also established schools to train men of talent and ability for national examinations, and also they used trained bureaucrats to run their government and this lasted till the 20th century

Iwould like a photo instead of all this and you can’t just go out asking for a paragraph thinking someone will be like oh yeah here it is