Average spending per resident

I wonder what the average allocatable government /tax spending is per person in this area, and how does it vary within the area? In other words, we all benefit from a certain number of government expenditures and so those - like road maintenance - should simply get divided among jurisdiction populations. Other expenditures, such as support for the senior center or for schools, can be allocated more finely. In the end, we should be able to know what amount of money and for what purposes gets spent for each of us depending on who we are. Again, for example, this might be a 70 year old resident, a 12 year old, a single mother or father with x kids, etc. Even students might be a category. Good exercise? Already done?
More generally, we might have an idea on average spending for residents 18 or younger v. 60 or older...or whatever age breakdowns make sense and also divided according to jurisdiction.