{
  "_instructions": [
    "手动更新时：修改 updated_at，并在 rates 数组末尾添加新一期。",
    "fixed_rate 是固定年利率，semiannual_inflation_rate 是财政部官方半年通胀率。",
    "利率用百分数数值填写，例如 1.40，而不是 0.014；不要加百分号。最多保留两位小数。",
    "date 格式为 YYYY-MM-01。年化浮动部分、综合利率、最新数字、日期、算例及高低点均自动生成。"
  ],
  "updated_at": "2026-10-31",
  "source_url": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/",
  "rates": [
    {
      "date": "1998-09-01",
      "fixed_rate": 3.4,
      "semiannual_inflation_rate": 0.62
    },
    {
      "date": "1998-11-01",
      "fixed_rate": 3.3,
      "semiannual_inflation_rate": 0.86
    },
    {
      "date": "1999-05-01",
      "fixed_rate": 3.3,
      "semiannual_inflation_rate": 0.86
    },
    {
      "date": "1999-11-01",
      "fixed_rate": 3.4,
      "semiannual_inflation_rate": 1.76
    },
    {
      "date": "2000-05-01",
      "fixed_rate": 3.6,
      "semiannual_inflation_rate": 1.91
    },
    {
      "date": "2000-11-01",
      "fixed_rate": 3.4,
      "semiannual_inflation_rate": 1.52
    },
    {
      "date": "2001-05-01",
      "fixed_rate": 3,
      "semiannual_inflation_rate": 1.44
    },
    {
      "date": "2001-11-01",
      "fixed_rate": 2,
      "semiannual_inflation_rate": 1.19
    },
    {
      "date": "2002-05-01",
      "fixed_rate": 2,
      "semiannual_inflation_rate": 0.28
    },
    {
      "date": "2002-11-01",
      "fixed_rate": 1.6,
      "semiannual_inflation_rate": 1.23
    },
    {
      "date": "2003-05-01",
      "fixed_rate": 1.1,
      "semiannual_inflation_rate": 1.77
    },
    {
      "date": "2003-11-01",
      "fixed_rate": 1.1,
      "semiannual_inflation_rate": 0.54
    },
    {
      "date": "2004-05-01",
      "fixed_rate": 1,
      "semiannual_inflation_rate": 1.19
    },
    {
      "date": "2004-11-01",
      "fixed_rate": 1,
      "semiannual_inflation_rate": 1.33
    },
    {
      "date": "2005-05-01",
      "fixed_rate": 1.2,
      "semiannual_inflation_rate": 1.79
    },
    {
      "date": "2005-11-01",
      "fixed_rate": 1,
      "semiannual_inflation_rate": 2.85
    },
    {
      "date": "2006-05-01",
      "fixed_rate": 1.4,
      "semiannual_inflation_rate": 0.5
    },
    {
      "date": "2006-11-01",
      "fixed_rate": 1.4,
      "semiannual_inflation_rate": 1.55
    },
    {
      "date": "2007-05-01",
      "fixed_rate": 1.3,
      "semiannual_inflation_rate": 1.21
    },
    {
      "date": "2007-11-01",
      "fixed_rate": 1.2,
      "semiannual_inflation_rate": 1.53
    },
    {
      "date": "2008-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 2.42
    },
    {
      "date": "2008-11-01",
      "fixed_rate": 0.7,
      "semiannual_inflation_rate": 2.46
    },
    {
      "date": "2009-05-01",
      "fixed_rate": 0.1,
      "semiannual_inflation_rate": -2.78
    },
    {
      "date": "2009-11-01",
      "fixed_rate": 0.3,
      "semiannual_inflation_rate": 1.53
    },
    {
      "date": "2010-05-01",
      "fixed_rate": 0.2,
      "semiannual_inflation_rate": 0.77
    },
    {
      "date": "2010-11-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 0.37
    },
    {
      "date": "2011-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 2.3
    },
    {
      "date": "2011-11-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 1.53
    },
    {
      "date": "2012-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 1.1
    },
    {
      "date": "2012-11-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 0.88
    },
    {
      "date": "2013-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 0.59
    },
    {
      "date": "2013-11-01",
      "fixed_rate": 0.2,
      "semiannual_inflation_rate": 0.59
    },
    {
      "date": "2014-05-01",
      "fixed_rate": 0.1,
      "semiannual_inflation_rate": 0.92
    },
    {
      "date": "2014-11-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 0.74
    },
    {
      "date": "2015-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": -0.8
    },
    {
      "date": "2015-11-01",
      "fixed_rate": 0.1,
      "semiannual_inflation_rate": 0.77
    },
    {
      "date": "2016-05-01",
      "fixed_rate": 0.1,
      "semiannual_inflation_rate": 0.08
    },
    {
      "date": "2016-11-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 1.38
    },
    {
      "date": "2017-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 0.98
    },
    {
      "date": "2017-11-01",
      "fixed_rate": 0.1,
      "semiannual_inflation_rate": 1.24
    },
    {
      "date": "2018-05-01",
      "fixed_rate": 0.3,
      "semiannual_inflation_rate": 1.11
    },
    {
      "date": "2018-11-01",
      "fixed_rate": 0.5,
      "semiannual_inflation_rate": 1.16
    },
    {
      "date": "2019-05-01",
      "fixed_rate": 0.5,
      "semiannual_inflation_rate": 0.7
    },
    {
      "date": "2019-11-01",
      "fixed_rate": 0.2,
      "semiannual_inflation_rate": 1.01
    },
    {
      "date": "2020-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 0.53
    },
    {
      "date": "2020-11-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 0.84
    },
    {
      "date": "2021-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 1.77
    },
    {
      "date": "2021-11-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 3.56
    },
    {
      "date": "2022-05-01",
      "fixed_rate": 0,
      "semiannual_inflation_rate": 4.81
    },
    {
      "date": "2022-11-01",
      "fixed_rate": 0.4,
      "semiannual_inflation_rate": 3.24
    },
    {
      "date": "2023-05-01",
      "fixed_rate": 0.9,
      "semiannual_inflation_rate": 1.69
    },
    {
      "date": "2023-11-01",
      "fixed_rate": 1.3,
      "semiannual_inflation_rate": 1.97
    },
    {
      "date": "2024-05-01",
      "fixed_rate": 1.3,
      "semiannual_inflation_rate": 1.48
    },
    {
      "date": "2024-11-01",
      "fixed_rate": 1.2,
      "semiannual_inflation_rate": 0.95
    },
    {
      "date": "2025-05-01",
      "fixed_rate": 1.1,
      "semiannual_inflation_rate": 1.43
    },
    {
      "date": "2025-11-01",
      "fixed_rate": 0.9,
      "semiannual_inflation_rate": 1.56
    },
    {
      "date": "2026-05-01",
      "fixed_rate": 0.9,
      "semiannual_inflation_rate": 1.67
    },
    {
      "date": "2026-11-01",
      "fixed_rate": 1.4,
      "semiannual_inflation_rate": 2.04
    }
  ]
}