PLEASE HELP Total world population (billions): 1804 1; 1922 2;
1959 3: 1974 4: 1987 5; 1999 6. Estimates for the
future (billions): 2013 7; 2028 8; 2048 9.
State the number of years taken for each
population increase of one billion (known
and estimated).

If a particular resource is not useful or needed then the price would be considerably low. once that resource is needed the price or value will raise depending on how useful or needed it is especially if the resource is low in quantity, the consumers would pay whatever they have to, to get that material.

Answerspring and autumn

Yeah, i guess that checks out because the unused brain is almost like a clean slate or a new car. it has more value than an older already used brain. -thomasnash

Ibelive it  is a yazoo tributary