This claim is a scaled claim that pays an amount based on the relative ratio of "Net exports of goods and services" versus "GDP" as reported by the US Bureau of Economic Analysis (or BEA) in the first report on the US GDP of the last quarter of 2008. Let $EXPORTS be the BEA's reported "Net exports of goods and services" figure (different of net exports minus net imports) in chained dollars (inflation adjusted). Similiarly, let $GDP be the GDP reported by the BEA in chained dollars. Then the payout to YES holders will be -(0.025 + $EXPORTS/$GDP)*2000 rounded to the nearest digit with minimum payout of 0 and maximum payout of 100.
Note that the export figure is reported as a negative number when the import figure is greater than the export figure (so lower negative numbers means larger trade deficits). Further, the BEA may estimate in advance these GDP figures and probably will revise these figures in the months after they are issued. The report that counts is the first unrevised report issued on the quarter in question by the BEA. If this report is no longer issued, then the judge may use his or her judgement in finding inflation-adjusted GDP figures for the US. Preference should be given to US government sources.
Payout Summary:
http://www.bea.gov/newsreleases/national/gdp/2009/pdf/gdp408a.pdf
See Table 3. I get -356.4 billion for $EXPORTS (fourth quarter 2008, chained dollars) and 11,599.4 billion for $GDP. After making the calculation, I get 11.45 for the payout to YES coupons, rounded to the nearest digit, that should be 11 paid to YES holders.