note 9 . retirement plan we maintain a defined contribution pension plan covering full-time shoreside employees who have completed the minimum period of continuous service . annual contributions to the plan are based on fixed percentages of participants 2019 salaries and years of service , not to exceed certain maximums . pension cost was $ 13.9 million , $ 12.8 million and $ 12.2 million for the years ended december 31 , 2006 , 2005 and 2004 , respectively . note 10 . income taxes we and the majority of our subsidiaries are currently exempt from united states corporate tax on income from the international opera- tion of ships pursuant to section 883 of the internal revenue code . income tax expense related to our remaining subsidiaries was not significant for the years ended december 31 , 2006 , 2005 and 2004 . final regulations under section 883 were published on august 26 , 2003 , and were effective for the year ended december 31 , 2005 . these regulations confirmed that we qualify for the exemption provid- ed by section 883 , but also narrowed the scope of activities which are considered by the internal revenue service to be incidental to the international operation of ships . the activities listed in the regula- tions as not being incidental to the international operation of ships include income from the sale of air and other transportation such as transfers , shore excursions and pre and post cruise tours . to the extent the income from such activities is earned from sources within the united states , such income will be subject to united states taxa- tion . the application of these new regulations reduced our net income for the years ended december 31 , 2006 and december 31 , 2005 by approximately $ 6.3 million and $ 14.0 million , respectively . note 11 . financial instruments the estimated fair values of our financial instruments are as follows ( in thousands ) : .

2006: cash and cash equivalents: 104520
long-term debt ( including current portion of long-term debt ): -5474988
foreign currency forward contracts in a net ( loss ) gain position: 104159
interest rate swap agreements in a net receivable position: 5856
fuel swap agreements in a net payable position: -20456
2005: cash and cash equivalents: 125385
long-term debt ( including current portion of long-term debt ): -4368874
foreign currency forward contracts in a net ( loss ) gain position: -115415
interest rate swap agreements in a net receivable position: 8456
fuel swap agreements in a net payable position: -78

long-term debt ( including current portion of long-term debt ) ( 5474988 ) ( 4368874 ) foreign currency forward contracts in a net ( loss ) gain position 104159 ( 115415 ) interest rate swap agreements in a net receivable position 5856 8456 fuel swap agreements in a net payable position ( 20456 ) ( 78 ) the reported fair values are based on a variety of factors and assumptions . accordingly , the fair values may not represent actual values of the financial instruments that could have been realized as of december 31 , 2006 or 2005 , or that will be realized in the future and do not include expenses that could be incurred in an actual sale or settlement . our financial instruments are not held for trading or speculative purposes . our exposure under foreign currency contracts , interest rate and fuel swap agreements is limited to the cost of replacing the contracts in the event of non-performance by the counterparties to the contracts , all of which are currently our lending banks . to minimize this risk , we select counterparties with credit risks acceptable to us and we limit our exposure to an individual counterparty . furthermore , all foreign currency forward contracts are denominated in primary currencies . cash and cash equivalents the carrying amounts of cash and cash equivalents approximate their fair values due to the short maturity of these instruments . long-term debt the fair values of our senior notes and senior debentures were esti- mated by obtaining quoted market prices . the fair values of all other debt were estimated using discounted cash flow analyses based on market rates available to us for similar debt with the same remaining maturities . foreign currency contracts the fair values of our foreign currency forward contracts were esti- mated using current market prices for similar instruments . our expo- sure to market risk for fluctuations in foreign currency exchange rates relates to six ship construction contracts and forecasted transactions . we use foreign currency forward contracts to mitigate the impact of fluctuations in foreign currency exchange rates . as of december 31 , 2006 , we had foreign currency forward contracts in a notional amount of $ 3.8 billion maturing through 2009 . as of december 31 , 2006 , the fair value of our foreign currency forward contracts related to the six ship construction contracts , which are designated as fair value hedges , was a net unrealized gain of approximately $ 106.3 mil- lion . at december 31 , 2005 , the fair value of our foreign currency for- ward contracts related to three ship construction contracts , designated as fair value hedges , was a net unrealized loss of approx- imately $ 103.4 million . the fair value of our foreign currency forward contracts related to the other ship construction contract at december 31 , 2005 , which was designated as a cash flow hedge , was an unre- alized loss , of approximately $ 7.8 million . at december 31 , 2006 , approximately 11% ( 11 % ) of the aggregate cost of the ships was exposed to fluctuations in the euro exchange rate . r o y a l c a r i b b e a n c r u i s e s l t d . 3 5 notes to the consolidated financial statements ( continued ) 51392_financials-v9.qxp 6/7/07 3:40 pm page 35 .

Questions:
what was the pension cost in 2006, in millions?
and what was it in 2005, also in millions?
what was, then, the total pension cost for the two years, in millions?
what was the pension cost in 2004, in millions?
including now 2004, what would then be, in millions, the total pension cost for the three years?

Answers:
13.9
12.8
26.7
12.2
38.9