The network has a “reserve” that contains pre-circulated tokens. Tokens from this reserve (which is owned and operated by the network, not the treasury) are emitted into the network each block. The block rewards (b) is the reserve (r) divided by emission curve (e) divided by blocks per year (y)
$$ b = (r / e) / y $$
Block rewards are distributed to validators pro rata based on bond size.
Data host collect income from consumers of their API, they can establish their own pricing as desired. Some small percentage of Data Host income gets sent into the reserve. This amount (in basis points) can be determined by (p) (10%) divided by target block height (b) divided by current block height (c).
$$ pts = p / (b / c) $$