{
  "query_note": "race_results.entry_position を実測スタートコース、boat_number を固定枠番として使用。両者不一致(全体の約10.3%, 2021-)を『進入変更があった』とみなす(変更の理由はデータ上区別できない)",
  "yearly_kept_course1_pct_2019_2026": [
    {"yr": 2026, "total": 34617, "kept_course1": 34239, "pct_kept": 98.91},
    {"yr": 2025, "total": 51514, "kept_course1": 50960, "pct_kept": 98.92},
    {"yr": 2024, "total": 51856, "kept_course1": 51398, "pct_kept": 99.12},
    {"yr": 2023, "total": 52037, "kept_course1": 51564, "pct_kept": 99.09},
    {"yr": 2022, "total": 52021, "kept_course1": 51465, "pct_kept": 98.93},
    {"yr": 2021, "total": 51581, "kept_course1": 51046, "pct_kept": 98.96},
    {"yr": 2020, "total": 51480, "kept_course1": 50736, "pct_kept": 98.55},
    {"yr": 2019, "total": 51348, "kept_course1": 50524, "pct_kept": 98.40}
  ],
  "main_comparison_2021_2026": [
    {"group_label": "1コースのまま", "n": 290672, "wins": 162308, "win_pct": 55.84, "top2": 213429, "top2_pct": 73.43, "top3": 239432, "top3_pct": 82.37},
    {"group_label": "実測1コースを外れた", "n": 2954, "wins": 387, "win_pct": 13.10, "top2": 922, "top2_pct": 31.21, "top3": 1394, "top3_pct": 47.19}
  ],
  "pushed_out_breakdown_by_destination_course_2021_2026": [
    {"entry_position": 2, "n": 2423, "wins": 309, "win_pct": 12.75},
    {"entry_position": 3, "n": 314, "wins": 37, "win_pct": 11.78},
    {"entry_position": 4, "n": 81, "wins": 18, "win_pct": 22.22},
    {"entry_position": 5, "n": 55, "wins": 14, "win_pct": 25.45},
    {"entry_position": 6, "n": 81, "wins": 9, "win_pct": 11.11}
  ],
  "note_on_small_n": "entry_position 4/5/6への押し出しはn=55〜81と少なく、win_pctの上下は誤差の範囲。本文では『1コースのまま』vs『押し出された全体』の対比のみを主張根拠とし、押し出し先コース別の細分は参考表に留める"
}