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FINANCIAL HIGHLIGHTS (Details) - $ / shares | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Per Share Operating Performance: |  |  |
Net asset value, beginning of year | $ 27.81 | $ 17.23 | $ 22.95
Total income (loss) | 7.95 | 10.79 | (5.59)
Total expenses | (0.31) | (0.21) | (0.13)
Net increase (decrease) in net asset value | 7.64 | 10.58 | (5.72)
Net asset value, end of year | $ 35.45 | $ 27.81 | $ 17.23
Total Return | 27.47% | 61.40% | (24.92%)
Ratios to Average Net Assets |  |  |
Total income (loss) | 31.17% | 53.01% | 61.24%
Management fees | 0.60% | 0.60% | 0.60%
Total expenses excluding management fees | 0.25% | 0.30% | 0.28%
Net income (loss) | 30.32% | 52.11% | 60.36%

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