A transit lounge?

According to Peter Dunne, New Zealand is "a giant transit lounge for Australia" because "nearly 20%" (19% - 19.6%, depending on how close one of their rounded figures is) of the New Zealanders emigrating to Australia were born overseas. It sounds compelling, except for one thing: that's actually lower than the equivalent proportion of the general population. According to the 2006 census, 22.9% of those ordinarily resident in New Zealand were born overseas. You'd think someone might have bothered to check that first, but who cares about facts when you're trying to whip up an election-year immigration scare?