Solve the Problem $\$ 0.13$ Billion Per Year
B) Decrease Of $\$ 0.33$

Solve the problem.
-Data regarding the amount spent by a government department is represented in the following graph. Find the rate of change of the amount spent with respect to time, in billions per year.

A) Increase of $\$ 0.13$ billion per year
B) Decrease of $\$ 0.33$ billion per year
C) Decrease of $\$ 0.23$ billion per year
D) Increase of $\$ 0.23$ billion per year