Answer
$119$ billion
Work Step by Step
The formula for Constant rate of change is $\frac{△y}{△x}$. Let's take 2 sets of coordinates and plug it in to this formula.
$\frac{1,838,000,000,000 - 1,243,000,000,000}{2005-2000} = \frac{595,000,000,000}{5} =119,000,000,000 $
The constant rate of change is $119$ billion.
