The statements that represent exponential functions are:
- The price of houses in this neighborhood is increasing at the rate of about \(3\%\) per year.
- The value of a car depreciates at a rate of \(22\%\) per year.
- The population of your home town is doubling every 12 years.
Thus, the answer is:
\[
\boxed{\text{Statements 2, 3, and 4 are exponential functions.}}
\]