Wood Products sales in the United States in 2005 of $1.6 billion were up 3% from $1.5 billion in 2004 and 18% from $1.3 billion in 2003.
Average price realizations for lumber were up 6% and 21% in 2005 compared with 2004 and 2003, respectively.
Lumber sales volumes in 2005 were up 5% versus 2004 and 10% versus 2003.
Average sales prices for plywood were down 4% from 2004, but were 15% higher than in 2003.
Plywood sales volumes in 2005 were slightly higher than 2004 and 2003.
Operating profits in 2005 were 18% lower than 2004, but nearly three times higher than 2003.
Lower average plywood prices and higher raw material costs more than offset the effects of higher average lumber prices, volume increases and a positive sales mix.
In 2005, log costs were up 9% versus 2004, negatively impacting both plywood and lumber profits.
Lumber and plywood operating costs also reflected substantially higher glue and natural gas costs versus both 2004 and 2003.
Looking forward to the first quarter of 2006, a continued strong housing market, combined with low product inventory in the distribution chain, should translate into continued strong lumber and plywood demand.
However, a possible softening of housing starts and higher interest rates later in the year could put downward pressure on pricing in the second half of 2006.
Specialty Businesses and Other The Specialty Businesses and Other segment includes the operating results of Arizona Chemical, European Distribution and, prior to its closure in 2003, our Natchez, Mississippi chemical cellulose pulp mill.
Also included are certain divested businesses whose results are included in this segment for periods prior to their sale or closure.
This segment’s 2005 net sales declined 18% and 26% from 2004 and 2003, respectively.
Operating profits in 2005 were down substantially from both 2004 and 2003.
The decline in sales principally reflects declining contributions from businesses sold or closed.
Operating profits were also affected by higher energy and raw material costs in our Chemical business.
## Table 0 ##
Chemicals sales were $692 million in 2005, compared with $672 million in 2004 and $625 million in 2003.
Although demand was strong for most Arizona Chemical product lines, operating profits in 2005 were 84% and 83% lower than in 2004 and 2003, respectively, due to higher energy costs in the U. S. , and higher prices and reduced availability for crude tall oil (CTO).
In the United States, energy costs increased 41% compared to 2004 due to higher natural gas prices and supply interruption costs.
CTO prices increased 26% compared to 2004, as certain energy users turned to CTO as a substitute fuel for high-cost alternative energy sources such as natural gas and fuel oil.
European CTO receipts decreased 30% compared to 2004 due to lower yields following the Finnish paper industry strike and a Swedish storm that limited CTO throughput and corresponding sales volumes.
Other businesses in this operating segment include operations that have been sold, closed, or are held for sale, principally the European Distribution business, the oil and gas and mineral royalty business, Decorative Products, Retail Packaging, and the Natchez chemical cellulose pulp mill.
Sales for these businesses were approximately $223 million in 2005 (mainly European Distribution and Decorative Products) compared with $448 million in 2004 (mainly European Distribution and Decorative Products), and $610 million in 2003.
LIQUIDITY AND CAPITAL RESOURCES Overview A major factor in International Paper’s liquidity and capital resource planning is its generation of operating cash flow, which is highly sensitive to changes in the pricing and demand for our major products.
While changes in key cash operating costs, such as energy and raw material costs, do have an effect on operating cash generation, we believe that our strong focus on cost controls has improved our cash flow generation over an operating cycle.
As a result, we believe that we are well positioned for improvements in operating cash flow should prices and worldwide economic conditions improve in the future.
As part of our continuing focus on improving our return on investment, we have focused our capital spending on improving our key platform businesses in North America and in geographic areas with strong growth opportunities.
Spending levels have been kept below the level of depreciation and amortization charges for each of the last three years, and we anticipate continuing this approach in 2006.
With the low interest rate environment in 2005, financing activities have focused largely on the repayment or refinancing of higher coupon debt, resulting in a net reduction in debt of approximately $1.7 billion in 2005.
We plan to continue this program, with additional reductions anticipated as our previously announced Transformation Plan progresses in 2006.
Our liquidity position continues to be strong, with approximately $3.2 billion of committed liquidity to cover future short-term cash flow requirements not met by operating cash flows.
REGENERON PHARMACEUTICALS, INC.  NOTES TO FINANCIAL STATEMENTS (Continued) For the years ended December 31, 2009, 2008, and 2007 (Unless otherwise noted, dollars in thousands, except per share data) At December 31, 2009 and 2008, marketable securities included an additional unrealized gain of $1.4 million and an additional unrealized loss of $0.4 million, respectively, related to one equity security in the Company’s marketable securities portfolio.
The following table shows the fair value of the Company’s marketable securities that have unrealized losses and that are deemed to be only temporarily impaired, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position, at December 31, 2009 and 2008.
The debt securities listed at December 31, 2009 mature at various dates through December 2011.
## Table 1 ##
Realized gains and losses are included as a component of investment income.
For the years ended December 31, 2009 and 2008, realized gains on sales of marketable securities totaled $0.2 million and $1.2 million, respectively, and realized losses on sales of marketable securities were not significant.
For the year ended December 31, 2007, realized gains and losses on sales of marketable securities were not significant.
In computing realized gains and losses, the Company computes the cost of its investments on a specific identification basis.
Such cost includes the direct costs to acquire the security, adjusted for the amortization of any discount or premium.
The Company’s assets that are measured at fair value on a recurring basis, at December 31, 2009 and 2008, were as follows:
## Table 2 ##
The decrease in total Non-cash Compensation Expense in 2009 was primarily attributable to the lower fair market value of our Common Stock on the date of our annual employee option grants made in December 2008 as compared to the fair market value of annual employee option grants made in recent years prior to 2008.
Research and Development Expenses Research and development expenses increased to $398.4 million in 2009 from $274.9 million in 2008.
The following table summarizes the major categories of our research and development expenses in 2009 and 2008:

<table><tr><td><i>In millions</i></td><td>2005</td><td>2004</td><td>2003</td></tr><tr><td>Sales</td><td>$915</td><td>$1,120</td><td>$1,235</td></tr><tr><td>Operating Profit</td><td>$4</td><td>$38</td><td>$23</td></tr></table>
<table><tr><td></td><td colspan="2">Less than 12 Months</td><td colspan="2">12 Months or Greater</td><td colspan="2">Total</td></tr><tr><td>At December 31, 2009</td><td>Fair Value</td><td>Unrealized Loss</td><td>Fair Value</td><td>Unrealized Loss</td><td>Fair Value</td><td>Unrealized Loss</td></tr><tr><td>U.S. government obligations</td><td>$ 9,367</td><td>$ -46</td><td></td><td></td><td>$ 9,367</td><td>$ -46</td></tr><tr><td>Mortgage-backed securities</td><td></td><td></td><td>3,238</td><td>-401</td><td>3,238</td><td>-401</td></tr><tr><td></td><td>$ 9,367</td><td>$ -46</td><td>$ 3,238</td><td>$-401</td><td>$12,605</td><td>$ -447</td></tr><tr><td>At December 31, 2008</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Corporate bonds</td><td>$15,559</td><td>$-287</td><td>$ 2,933</td><td>$ -79</td><td>$18,492</td><td>$ -366</td></tr><tr><td>Government guaranteed</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>corporate bonds</td><td>11,300</td><td>-124</td><td></td><td></td><td>11,300</td><td>-124</td></tr><tr><td>Mortgage-backed securities</td><td>871</td><td>-74</td><td>9,104</td><td>-869</td><td>9,975</td><td>-943</td></tr><tr><td>Other asset-backed securities</td><td>7,829</td><td>-13</td><td></td><td></td><td>7,829</td><td>-13</td></tr><tr><td>Equity securities</td><td>3,608</td><td>-436</td><td></td><td></td><td>3,608</td><td>-436</td></tr><tr><td></td><td>$39,167</td><td>$-934</td><td>$12,037</td><td>$-948</td><td>$51,204</td><td>$-1,882</td></tr></table>
<table><tr><td></td><td></td><td colspan="3">Fair Value Measurements at Reporting Date Using</td></tr><tr><td>Description</td><td>Fair Value at December 31, 2009</td><td>Quoted Prices in Active Markets for Identical Assets (Level 1)</td><td>Significant Other Observable Inputs (Level 2)</td><td>Significant Unobservable Inputs (Level 3)</td></tr><tr><td>Available-for-sale marketable securities</td><td></td><td></td><td></td><td></td></tr><tr><td>U.S. government obligations</td><td>$109,940</td><td></td><td>$109,940</td><td></td></tr><tr><td>U.S. government guaranteed</td><td></td><td></td><td></td><td></td></tr><tr><td>corporate bonds</td><td>48,684</td><td></td><td>48,684</td><td></td></tr><tr><td>Corporate bonds</td><td>10,342</td><td></td><td>10,342</td><td></td></tr><tr><td>Mortgage-backed securities</td><td>3,238</td><td></td><td>3,238</td><td></td></tr><tr><td>U.S. government guaranteed</td><td></td><td></td><td></td><td></td></tr><tr><td>collateralized mortgage obligations</td><td>3,662</td><td></td><td>3,662</td><td></td></tr><tr><td>Equity securities</td><td>5,469</td><td>5,469</td><td></td><td></td></tr><tr><td>Total</td><td>$181,335</td><td>$5,469</td><td>$175,866</td><td></td></tr></table>

Question: Which year has the greatest proportion of Mortgage-backed securities in total of fair value?