You can use the following Cost of Gas calculator to estimate how much you are spending on gasoline in an average month from this it will estimate your average cost of gas per year as well.
South Africa Population growth rate. Factbook > Countries > South Africa > Demographics. Population growth rate: 0.99% (2016 est.) Definition: The average annual percent change in the population, resulting from a surplus (or deficit) of births over deaths and the balance of migrants entering and leaving a country. The rate may be positive or negative.
Population growth rates vary by world region, with the highest growth rates in Sub-Saharan Africa and the lowest in Europe. For example, from 1950 to 2010, Sub-Saharan African grew over three and a half times, from about 186 million to 856 million.