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FINANCIAL HIGHLIGHTS | 12 Months Ended
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Dec. 31, 2012
Financial Highlights [Abstract] |
Financial Highlights | NOTE 6 - FINANCIAL HIGHLIGHTS The following table presents per unit performance data and other supplemental financial data for the years ended December 31, 2012, 2011 and 2010. This information has been derived from information presented in the financial statements.
|  | Year Ended December 31, 2012 |  |  | Year Ended December 31, 2011 |  |  | Year Ended December 31, 2010 |
Per Unit Operating Performance: |  |  |  |  |  |  |  |  |  |  |  |
Net asset value, beginning of year |  | $ | 21.21 |  |  | $ | 35.02 |  |  | $ | 53.77 |
Total income (loss) |  |  | (3.78 | ) |  |  | (13.42 | ) |  |  | (18.21 | )
Net expenses |  |  | (0.20 | ) |  |  | (0.39 | ) |  |  | (0.54 | )
Net decrease in net asset value |  |  | (3.98 | ) |  |  | (13.81 | ) |  |  | (18.75 | )
Net asset value, end of year |  | $ | 17.23 |  |  | $ | 21.21 |  |  | $ | 35.02 |
Total Return |  |  | (18.76 | )% |  |  | (39.43 | )% |  |  | (34.87 | )%
Ratios to Average Net Assets |  |  |  |  |  |  |  |  |  |  |  |
Total income (loss) |  |  | (11.80 | )% |  |  | (44.03 | )% |  |  | (37.65 | )%
Management fees |  |  | 0.75 | % |  |  | 0.75 | % |  |  | 0.70 | %
Total expenses excluding management fees |  |  | 0.40 | % |  |  | 0.53 | % |  |  | 0.66 | %
Expenses waived |  |  | (0.18 | )% |  |  | (0.36 | )% |  |  | (0.43 | )%
Net expenses excluding management fees |  |  | 0.22 | % |  |  | 0.17 | % |  |  | 0.23 | %
Net income (loss) |  |  | (12.77 | )% |  |  | (44.95 | )% |  |  | (38.58 | )%
Total returns are calculated based on the change in value during the period. An individual unitholder’s total return and ratio may vary from the above total returns and ratios based on the timing of contributions to and withdrawals from US12NG.

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