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v3.20.4

SUBSEQUENT EVENTS (Details) | 12 Months Ended | 161 Months Ended
--- | --- | ---
Dec. 31, 2020 USD ($) shares | Dec. 31, 2019 USD ($) shares | Dec. 31, 2020 USD ($) $ / item shares
Subsequent events |  |  |
Number of depository receipts repurchased |  |  | 1,428,437
Repurchase price of depository receipts (in dollars per receipt) | $ / item |  |  | 28.43
Total cost of repurchase | $ | $ 394,031 | $ 4,050,137 | $ 44,718,000
Units required to be repurchased (in shares) | 222 | 2,408 |
Class B |  |  |
Subsequent events |  |  |
Number of depository receipts repurchased |  |  | 3,572
Total cost of repurchase | $ | $ 74,870 | $ 769,458 |
Units required to be repurchased (in shares) | 42.18 | 457.6 |
General Partnership |  |  |
Subsequent events |  |  |
Number of depository receipts repurchased |  |  | 188
Total cost of repurchase | $ | $ 3,941 | $ 40,498 |
Units required to be repurchased (in shares) | 2.22 | 24.1 |

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- Definition Units that were previously issued and have been repurchased during the year. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB TOPIC 4.F) -URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187171-122770 + Details
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