The 7 must-know numbers of the week

The amount that Formula One driver Mark Webber spent on his Noosa retreat. Webber bought the property, which last sold for $3.5 million in early 2006, from tennis ace Thomas Muster.

The vacancy rate in Melbourne's iconic laneway retail arcades. Overall retail vacancy in the Melbourne CBD stands at 2%.

The decline in new home approvals in New South Wales for the month of May, according to ABS figures. Only 1,394 new homes were approved, the second-worst May approval figure since the ABS started keeping records.

The average cost of a house in the WA town of Karratha, and the average rental yield is 10.5%, according to REIWA figures. The mining boom has created one of the tightest rental markets in Australia.

The decline in the number of mortgage broking firms operating in Australia over the year to March 2011, according to new figures from Market Intelligence Strategy Centre.

The number of buyers whose first property purchase is an investment property, rather than a home to live in themselves.

The discount being offered on some properties in south-east Western Australia, where a massive oversupply of housing, a shrinking tourism market and the contraction of the wine industry have led to a very soft housing market.