It is a topic that should interest all Australians as much as it does property developers and investors. It is the number of net new residents (as opposed to babies) that is added to this nation every year. It is the rate of immigration, the number of refugees and asylum seekers; it is the number of new permanent residents, all of which are very different concepts but together they drive demand for housing in this nation.Migrants have swept across the Australian continent washing into every nook and cranny. A shorthand way of thinking about this is that the level of net overseas migration has ranged from barely 30,000 in 1993 to almost 300,000 in 2009. Immigration rises and falls depending on government policy and the perceived attractiveness of a destination.