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.
The population was estimated at 68,126 in 2000, giving a population density of 375 persons per square kilometer (971 per square mile), quite a bit higher than in neighboring island states in the Pacific. The population was estimated to be growing at 3.9 percent a year in 2000, which is considered a very rapid rate.