Table A11.

Annual United States national industrial natural gas costs 1999-2019.

Year	Average Nominal Cost Per Year (USD Thousand Cubic Feet−1)	Inflation Adjusted Cost (Cents Kwh−1)
1999	3.08	1.55
2000	4.45	2.19
2001	5.08	2.40
2002	4.02	1.88
2003	5.91	2.70
2004	6.51	2.92
2005	8.67	3.77
2006	7.82	2.58
2007	7.65	3.13
2008	9.66	3.79
2009	5.23	2.05
2010	5.44	2.08
2011	5.12	1.93
2012	3.85	1.41
2013	4.64	1.67
2014	5.58	1.98
2015	3.91	1.39
2016	3.49	1.22
2017	4.08	1.39
2018	4.17	1.42

Annual United States national average natural gas costs 1999–2019. Information was obtained from the United States EIA and average costs were normalized to January 2019 US currency [40,42].