page 29 of 98 in connection with the internal revenue service 2019s ( irs ) examination of ball 2019s consolidated income tax returns for the tax years 2000 through 2004 , the irs has proposed to disallow ball 2019s deductions of interest expense incurred on loans under a company-owned life insurance plan that has been in place for more than 20 years .
ball believes that its interest deductions will be sustained as filed and , therefore , no provision for loss has been recorded .
the total potential liability for the audit years 1999 through 2004 , unaudited year 2005 and an estimate of the impact on 2006 is approximately $ 31 million , excluding related interest .
the irs has withdrawn its proposed adjustments for any penalties .
see note 13 accompanying the consolidated financial statements within item 8 of this annual report .
results of equity affiliates equity in the earnings of affiliates in 2006 is primarily attributable to our 50 percent ownership in packaging investments in the u.s .
and brazil .
earnings in 2004 included the results of a minority-owned aerospace business , which was sold in october 2005 , and a $ 15.2 million loss representing ball 2019s share of a provision for doubtful accounts relating to its 35 percent interest in sanshui jfp ( discussed above in 201cmetal beverage packaging , europe/asia 201d ) .
after consideration of the prc loss , earnings were $ 14.7 million in 2006 compared to $ 15.5 million in 2005 and $ 15.8 million in 2004 .
critical and significant accounting policies and new accounting pronouncements for information regarding the company 2019s critical and significant accounting policies , as well as recent accounting pronouncements , see note 1 to the consolidated financial statements within item 8 of this report .
financial condition , liquidity and capital resources cash flows and capital expenditures cash flows from operating activities were $ 401.4 million in 2006 compared to $ 558.8 million in 2005 and $ 535.9 million in 2004 .
management internally uses a free cash flow measure : ( 1 ) to evaluate the company 2019s operating results , ( 2 ) for planning purposes , ( 3 ) to evaluate strategic investments and ( 4 ) to evaluate the company 2019s ability to incur and service debt .
free cash flow is not a defined term under u.s .
generally accepted accounting principles , and it should not be inferred that the entire free cash flow amount is available for discretionary expenditures .
the company defines free cash flow as cash flow from operating activities less additions to property , plant and equipment ( capital spending ) .
free cash flow is typically derived directly from the company 2019s cash flow statements ; however , it may be adjusted for items that affect comparability between periods .
an example of such an item included in 2006 is the property insurance proceeds for the replacement of the fire-damaged assets in our hassloch , germany , plant , which is included in capital spending amounts .
based on this , our consolidated free cash flow is summarized as follows: .

($ in millions)
2006
2005
2004
Cash flows from operating activities
$401.4
$558.8
$535.9
Capital spending
(279.6)
(291.7)
(196.0)
Proceeds for replacement of fire-damaged assets
61.3
–
–
Free cash flow
$183.1
$267.1
$339.9

cash flows from operating activities in 2006 were negatively affected by higher cash pension funding and higher working capital levels compared to the prior year .
the higher working capital was a combination of higher than planned raw material inventory levels , higher income tax payments and higher accounts receivable balances , the latter resulting primarily from the repayment of a portion of the accounts receivable securitization program and late payments from customers in europe .
management expects the increase in working capital to be temporary and that working capital levels will return to normal levels by the end of the first half of 2007. .

Question: Analyse this data from a financial earnings document. what was the difference in free cash flow between 2004 and 2005 in millions?
Choices:
-310.9
-156.8
-72.8
474.2
-535.9
Correct choice index: 2