no .
159 requires that unrealized gains and losses on items for which the fair value option has been elected be reported in earnings at each reporting date .
sfas no .
159 is effective for fiscal years beginning after november 15 , 2007 and is required to be adopted by the company beginning in the first quarter of fiscal 2009 .
although the company will continue to evaluate the application of sfas no .
159 , management does not currently believe adoption will have a material impact on the company 2019s financial condition or operating results .
in september 2006 , the fasb issued sfas no .
157 , fair value measurements , which defines fair value , provides a framework for measuring fair value , and expands the disclosures required for fair value measurements .
sfas no .
157 applies to other accounting pronouncements that require fair value measurements ; it does not require any new fair value measurements .
sfas no .
157 is effective for fiscal years beginning after november 15 , 2007 and is required to be adopted by the company beginning in the first quarter of fiscal 2009 .
although the company will continue to evaluate the application of sfas no .
157 , management does not currently believe adoption will have a material impact on the company 2019s financial condition or operating results .
in june 2006 , the fasb issued fasb interpretation no .
( 2018 2018fin 2019 2019 ) 48 , accounting for uncertainty in income taxes-an interpretation of fasb statement no .
109 .
fin 48 clarifies the accounting for uncertainty in income taxes by creating a framework for how companies should recognize , measure , present , and disclose in their financial statements uncertain tax positions that they have taken or expect to take in a tax return .
fin 48 is effective for fiscal years beginning after december 15 , 2006 and is required to be adopted by the company beginning in the first quarter of fiscal 2008 .
although the company will continue to evaluate the application of fin 48 , management does not currently believe adoption will have a material impact on the company 2019s financial condition or operating results .
liquidity and capital resources the following table presents selected financial information and statistics for each of the last three fiscal years ( dollars in millions ) : september 29 , september 30 , september 24 , 2007 2006 2005 .

September 29, 2007
September 30, 2006
September 24, 2005
Cash, cash equivalents, and short-term investments
$15,386
$10,110
$8,261
Accounts receivable, net
$1,637
$1,252
$895
Inventory
$346
$270
$165
Working capital
$12,657
$8,066
$6,813
Annual operating cash flow
$5,470
$2,220
$2,535

as of september 29 , 2007 , the company had $ 15.4 billion in cash , cash equivalents , and short-term investments , an increase of $ 5.3 billion over the same balance at the end of september 30 , 2006 .
the principal components of this net increase were cash generated by operating activities of $ 5.5 billion , proceeds from the issuance of common stock under stock plans of $ 365 million and excess tax benefits from stock-based compensation of $ 377 million .
these increases were partially offset by payments for acquisitions of property , plant , and equipment of $ 735 million and payments for acquisitions of intangible assets of $ 251 million .
the company 2019s short-term investment portfolio is primarily invested in highly rated , liquid investments .
as of september 29 , 2007 and september 30 , 2006 , $ 6.5 billion and $ 4.1 billion , respectively , of the company 2019s cash , cash equivalents , and short-term investments were held by foreign subsidiaries and are generally based in u.s .
dollar-denominated holdings .
the company believes its existing balances of cash , cash equivalents , and short-term investments will be sufficient to satisfy its working capital needs , capital expenditures , outstanding commitments , and other liquidity requirements associated with its existing operations over the next 12 months. .

Question: Analyse this data from a financial earnings document. what was the change between september 29 , 2007 and september 30 , 2006 , of the company 2019s cash , cash equivalents , and short-term investments were held by foreign subsidiaries and based in u.s . dollar-denominated holdings , in billions?
Choices:
1.6
10.6
-2.4
2.4
1.4
Correct choice index: 3