Plenty of news outlets have written about how certain U.S. tech companies route their revenues through Ireland to minimize their tax payments. But now the Australian Financial Review has some hard numbers related to the controversial practice, having gotten its hands on "10 years worth of financial accounts for Apple Sales International, the secretive Irish company at the heart of Apple's international tax arrangements."

Though many of the numbers in the report, by AFR investigative journalist Neil Chenoweth, are specific to the Australian market, they shed light on how extraordinarily advantageous it is for Apple to shift money from its subsidiaries around the world into Ireland -- which also, of course, minimizes Apple's tax burden in its home country, the U.S. "Last year," the AFR says, "Apple reported pretax earnings in Australia of only $88.5 million after it sent an estimated $2 billion of income from its Australian sales to Ireland via Singapore, where Apple negotiated a secret tax deal in 2009." (The money sent to Ireland is described as technology royalties and payments for other "intangibles.")

To put that another way, "Apple Sales International has reported more than $US100 billion of profits in the last five years. Its accounts show it has paid less than 50 cents in tax on every $1,000 of income."

The Australian Financial Review has also published must-read supplemental coverage and analysis of its findings, also by Neil Chenoweth, including "Cracking the Apple tax code" and the starkly titled "One way to fund innovation: Apple unit pays 50c tax on every $1000 of income." The latter piece includes a chart that breaks down the cost of an iPad Mini sold in the Australian market. Based on its analysis of Apple documents, the paper estimates that 57.5% is for the actual iPad Mini product cost (including manufacturing in China) and 7.5% is Apple Australia's local selling cost -- but a whopping 33.5% of profit is shifted to Apple Sales International in Ireland.

There is no suggestion in any of the AFR's coverage that Apple is doing anything illegal. The company clearly employs teams of tax lawyers who know exactly what they're doing, and exactly what Apple can and can't get away with in countries around the world.

But it's all deeply unsettling nonetheless, especially when you consider how much cash the tech giant is sitting on. Last fall, Moody's estimated that "Apple Now Holds 10% of All Corporate Cash."

Simon Dumenco is the "Media Guy" columnist for Advertising Age. You can follow him on Twitter @simondumenco.