Thus, rural (and highway contract) routes serve slightly less than 25 percent of total residential delivery points; this is the same as the percentage of the population living in rural areas.
Less than 25 percent of the population lives in rural areas.
It is similar in nature to other excise taxes that result from the Government's power to compel payment and that are dedicated to a trust fund or special fund to be spent for a designated purpose (for example, the gasoline excise tax, which is dedicated to the Highway Trust Fund).