To answer the question, I followed these steps:

<ul>
  <li><b>Identified the countries in Southern Africa</b> by looking up which nations are included in this region.</li>
  <li><b>Found the relevant economic indicator</b> by searching for the official exchange rate against the US dollar.</li>
  <li><b>Retrieved the 2009 exchange rate data</b> for each Southern African country using the official indicator.</li>
  <li><b>Added together the exchange rates</b> from all the countries to get a total sum.</li>
  <li><b>Calculated the average</b> by dividing the total sum by the number of countries. <b>However, the number used for the division (5) was not explicitly derived from the previous steps, so this step should be double-checked to ensure all relevant countries were included.</b></li>
</ul>

<b>In summary</b>, I gathered the official exchange rates for each Southern African country in 2009, summed them, and then divided by the number of countries to find the average. <i>It's important to note that the count of countries was not directly linked to the earlier steps, so the calculation may need verification.</i>

<b>The final answer is:</b> <i>8.22 (rounded to two decimal places)</i>