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v3.19.1

FINANCIAL HIGHLIGHTS (Per Unit Performance Data and Other Supplemental Financial Data) (Details) - $ / shares | 3 Months Ended
--- | ---
Mar. 31, 2019 | Mar. 31, 2018
Per Share Operating Performance: |  |  |
Net asset value, beginning of year |  | $ 10.26 | $ 9.26
Total income (loss) |  | 0.26 | 0.05
Net expenses |  | (0.02) | (0.02)
Net increase (decrease) in net asset value |  | 0.24 | 0.03
Net asset value, end of year |  | $ 10.50 | $ 9.29
Total Return |  | 2.34% | 0.32%
Ratios to Average Net Assets |  |  |
Total income (loss) |  | 2.52% | 0.88%
Management fees | [1] | 0.75% | 0.75%
Total expenses excluding management fees | [1] | 1.88% | 1.08%
Expenses waived | [1] | (1.73%) | (0.93%)
Net expenses excluding management fees | [1] | 0.15% | 0.15%
Net income (loss) |  | 2.30% | 0.65%
[1] | Annualized.

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