To determine the years in which there was a budget deficit, we need to compare the revenue and expenditure for each year from 2001 through 2009. A budget deficit occurs when the expenditure is higher than the revenue.
Here is the table of revenue and expenditure with a comparison for each year:
[tex]\[
\begin{array}{|c|c|c|}
\hline
\text{Year} & \text{Revenue (in trillion \$)} & \text{Expenditure (in trillion \$)} \\
\hline
2001 & 8 & 6 \Rightarrow \text{No Deficit} \\
\hline
2002 & 5 & 7 \Rightarrow \text{Deficit} \\
\hline
2003 & 8 & 10 \Rightarrow \text{Deficit} \\
\hline
2004 & 9 & 7 \Rightarrow \text{No Deficit} \\
\hline
2005 & 15 & 18 \Rightarrow \text{Deficit} \\
\hline
2006 & 8 & 10 \Rightarrow \text{Deficit} \\
\hline
2007 & 6 & 4 \Rightarrow \text{No Deficit} \\
\hline
2008 & 2 & 4 \Rightarrow \text{Deficit} \\
\hline
2009 & 7 & 4 \Rightarrow \text{No Deficit} \\
\hline
\end{array}
\][/tex]
From the above comparisons, we can identify the years when the expenditure exceeded the revenue. These years are:
- 2002
- 2003
- 2005
- 2006
- 2008
So, in the years 2002, 2003, 2005, 2006, and 2008, there was a budget deficit.
