Source: US. Bureau of Labor Statistics
Release: Consumer Price Index
US. Bureau of Labor Statistics, Consumer Price Index for All Urban Consumers: Utility (piped) gas service in Size Class B/C (between 50,000 and 1,500,000 persons) [CUURX000SEHF02], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/CUURX000SEHF02/, July 7, 2015.