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      "switch_utc": "2022-02-16T23:00:00+00:00",
      "difference": 0.052499999999999325
    },
    {
      "from_contract": "ZWK22-CBOT",
      "to_contract": "ZWN22-CBOT",
      "decision_session": "2022-04-12",
      "old_volume": 15968,
      "new_volume": 27018,
      "switch_utc": "2022-04-12T22:00:00+00:00",
      "difference": 0.08249999999999957
    },
    {
      "from_contract": "ZWN22-CBOT",
      "to_contract": "ZWU22-CBOT",
      "decision_session": "2022-06-22",
      "old_volume": 21708,
      "new_volume": 31586,
      "switch_utc": "2022-06-22T22:00:00+00:00",
      "difference": 0.1225000000000005
    },
    {
      "from_contract": "ZWU22-CBOT",
      "to_contract": "ZWZ22-CBOT",
      "decision_session": "2022-08-16",
      "old_volume": 15991,
      "new_volume": 19794,
      "switch_utc": "2022-08-16T22:00:00+00:00",
      "difference": 0.17250000000000032
    },
    {
      "from_contract": "ZWZ22-CBOT",
      "to_contract": "ZWH23-CBOT",
      "decision_session": "2022-11-21",
      "old_volume": 17721,
      "new_volume": 21924,
      "switch_utc": "2022-11-21T23:00:00+00:00",
      "difference": 0.1849999999999996
    },
    {
      "from_contract": "ZWH23-CBOT",
      "to_contract": "ZWK23-CBOT",
      "decision_session": "2023-02-17",
      "old_volume": 11574,
      "new_volume": 15359,
      "switch_utc": "2023-02-19T23:00:00+00:00",
      "difference": 0.10749999999999993
    },
    {
      "from_contract": "ZWK23-CBOT",
      "to_contract": "ZWN23-CBOT",
      "decision_session": "2023-04-17",
      "old_volume": 27731,
      "new_volume": 31143,
      "switch_utc": "2023-04-17T22:00:00+00:00",
      "difference": 0.10749999999999993
    },
    {
      "from_contract": "ZWN23-CBOT",
      "to_contract": "ZWU23-CBOT",
      "decision_session": "2023-06-21",
      "old_volume": 39418,
      "new_volume": 43005,
      "switch_utc": "2023-06-21T22:00:00+00:00",
      "difference": 0.1324999999999994
    },
    {
      "from_contract": "ZWU23-CBOT",
      "to_contract": "ZWZ23-CBOT",
      "decision_session": "2023-08-15",
      "old_volume": 24596,
      "new_volume": 30520,
      "switch_utc": "2023-08-15T22:00:00+00:00",
      "difference": 0.2525000000000004
    },
    {
      "from_contract": "ZWZ23-CBOT",
      "to_contract": "ZWH24-CBOT",
      "decision_session": "2023-11-16",
      "old_volume": 32892,
      "new_volume": 35935,
      "switch_utc": "2023-11-16T23:00:00+00:00",
      "difference": 0.27000000000000046
    },
    {
      "from_contract": "ZWH24-CBOT",
      "to_contract": "ZWK24-CBOT",
      "decision_session": "2024-02-16",
      "old_volume": 25539,
      "new_volume": 28764,
      "switch_utc": "2024-02-18T23:00:00+00:00",
      "difference": -0.019999999999999574
    },
    {
      "from_contract": "ZWK24-CBOT",
      "to_contract": "ZWN24-CBOT",
      "decision_session": "2024-04-17",
      "old_volume": 19495,
      "new_volume": 33007,
      "switch_utc": "2024-04-17T22:00:00+00:00",
      "difference": 0.15249999999999986
    },
    {
      "from_contract": "ZWN24-CBOT",
      "to_contract": "ZWU24-CBOT",
      "decision_session": "2024-06-18",
      "old_volume": 32930,
      "new_volume": 35273,
      "switch_utc": "2024-06-18T22:00:00+00:00",
      "difference": 0.17250000000000032
    },
    {
      "from_contract": "ZWU24-CBOT",
      "to_contract": "ZWZ24-CBOT",
      "decision_session": "2024-08-19",
      "old_volume": 19977,
      "new_volume": 25732,
      "switch_utc": "2024-08-19T22:00:00+00:00",
      "difference": 0.23749999999999982
    },
    {
      "from_contract": "ZWZ24-CBOT",
      "to_contract": "ZWH25-CBOT",
      "decision_session": "2024-11-18",
      "old_volume": 33407,
      "new_volume": 34551,
      "switch_utc": "2024-11-18T23:00:00+00:00",
      "difference": 0.1825000000000001
    },
    {
      "from_contract": "ZWH25-CBOT",
      "to_contract": "ZWK25-CBOT",
      "decision_session": "2025-02-19",
      "old_volume": 31830,
      "new_volume": 42822,
      "switch_utc": "2025-02-19T23:00:00+00:00",
      "difference": 0.14499999999999957
    },
    {
      "from_contract": "ZWK25-CBOT",
      "to_contract": "ZWN25-CBOT",
      "decision_session": "2025-04-16",
      "old_volume": 24010,
      "new_volume": 32384,
      "switch_utc": "2025-04-16T22:00:00+00:00",
      "difference": 0.1299999999999999
    },
    {
      "from_contract": "ZWN25-CBOT",
      "to_contract": "ZWU25-CBOT",
      "decision_session": "2025-06-18",
      "old_volume": 60159,
      "new_volume": 70463,
      "switch_utc": "2025-06-18T22:00:00+00:00",
      "difference": 0.15999999999999925
    },
    {
      "from_contract": "ZWU25-CBOT",
      "to_contract": "ZWZ25-CBOT",
      "decision_session": "2025-08-15",
      "old_volume": 20216,
      "new_volume": 20907,
      "switch_utc": "2025-08-17T22:00:00+00:00",
      "difference": 0.20249999999999968
    },
    {
      "from_contract": "ZWZ25-CBOT",
      "to_contract": "ZWH26-CBOT",
      "decision_session": "2025-11-14",
      "old_volume": 44173,
      "new_volume": 51823,
      "switch_utc": "2025-11-16T23:00:00+00:00",
      "difference": 0.14250000000000007
    },
    {
      "from_contract": "ZWH26-CBOT",
      "to_contract": "ZWK26-CBOT",
      "decision_session": "2026-02-17",
      "old_volume": 40251,
      "new_volume": 47327,
      "switch_utc": "2026-02-17T23:00:00+00:00",
      "difference": 0.040000000000000036
    },
    {
      "from_contract": "ZWK26-CBOT",
      "to_contract": "ZWN26-CBOT",
      "decision_session": "2026-04-16",
      "old_volume": 36820,
      "new_volume": 39018,
      "switch_utc": "2026-04-16T22:00:00+00:00",
      "difference": 0.07999999999999918
    },
    {
      "from_contract": "ZWN26-CBOT",
      "to_contract": "ZWU26-CBOT",
      "decision_session": "2026-06-17",
      "old_volume": 35574,
      "new_volume": 44079,
      "switch_utc": "2026-06-17T22:00:00+00:00",
      "difference": 0.08000000000000007
    },
    {
      "from_contract": "ZWU26-CBOT",
      "to_contract": "ZWZ26-CBOT",
      "decision_session": "2026-08-14",
      "old_volume": 38173,
      "new_volume": 43584,
      "switch_utc": "2026-08-16T22:00:00+00:00",
      "difference": 0.14999999999999947
    }
  ]
}