>>216632110
Look at the numbers I've marked.
1.Number of burghers, as you see it's negative, that means that there's a demand for burghers.
To increase the demand for burghers, you have to build buildings, each building level can employ up to a certain amount, for production buildings is 200 per level, this means that if you have 1 single buildings you will get up to 200 burghers plus a number of unemployed burghers that depends on some modifiers, unemployed burghers would instantly get hired when you increase the building level or add a new building, peasants will promote at the promotion rate until they reach the maximum number of unemployed burghers.
2.Number of peasants, they generate some food, but less than food RGOs, when the number of burghers is negative, they will promote, same for laborers, soldiers, clergy and nobles.
To promote to laborers, you can build laborers buildings or expand RGOs, expanding RGOs increases the raw good produced in that area, for buildings you can choose what building to build depending on demand, I generally just order them in term of profitability but some times for example if you want to build libraries you can first build papermaker's guilds, then scriptoriums (clergy building) and then finally libraries.