{"updated": "2026-09-19", "title": "天然ガスは、いくらだったか", "source": "アメリカ エネルギー情報局（EIA）ヘンリーハブ スポット価格", "source_url": "https://www.eia.gov/dnav/ng/ng_pri_fut_s1_w.htm", "license": "CC BY 4.0（数値）", "method": "公表値の年ごとの平均。点が10未満の年は出さない", "series": {"henryhub": {"label": "ヘンリーハブ", "unit": "ドル", "yearly": [{"year": "1997", "avg": 2.491, "points": 51}, {"year": "1998", "avg": 2.097, "points": 52}, {"year": "1999", "avg": 2.262, "points": 53}, {"year": "2000", "avg": 4.317, "points": 52}, {"year": "2001", "avg": 3.976, "points": 52}, {"year": "2002", "avg": 3.36, "points": 52}, {"year": "2003", "avg": 5.458, "points": 52}, {"year": "2004", "avg": 5.887, "points": 53}, {"year": "2005", "avg": 8.777, "points": 51}, {"year": "2006", "avg": 6.737, "points": 52}, {"year": "2007", "avg": 6.957, "points": 52}, {"year": "2008", "avg": 8.886, "points": 52}, {"year": "2009", "avg": 3.941, "points": 52}, {"year": "2010", "avg": 4.402, "points": 53}, {"year": "2011", "avg": 3.995, "points": 52}, {"year": "2012", "avg": 2.752, "points": 52}, {"year": "2013", "avg": 3.726, "points": 52}, {"year": "2014", "avg": 4.39, "points": 52}, {"year": "2015", "avg": 2.64, "points": 52}, {"year": "2016", "avg": 2.512, "points": 53}, {"year": "2017", "avg": 2.989, "points": 52}, {"year": "2018", "avg": 3.182, "points": 52}, {"year": "2019", "avg": 2.568, "points": 52}, {"year": "2020", "avg": 2.028, "points": 52}, {"year": "2021", "avg": 3.894, "points": 53}, {"year": "2022", "avg": 6.436, "points": 52}, {"year": "2023", "avg": 2.537, "points": 52}, {"year": "2024", "avg": 2.187, "points": 52}, {"year": "2025", "avg": 3.516, "points": 52}, {"year": "2026", "avg": 3.578, "points": 37}]}}}