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Supplemental Information Gas: Btu Factors Navigator Btu Factors: 2008 | 2007 | 2006 Gas Transportation Btu Factors 2007 Illinois - Iowa - Nebraska - South Dakota Effective Month/Year Btu Factor* January 2007 1.010 February 2007 1.014 March 2007 1.018 April 2007 1.020 May 2007 1.020 June 2007 1.021 July 2007 1.022 August 2007 1.021 September 2007 1.018 October 2007 1.022 November 2007 1.020 December 2007 1.018 * This figure is a true weighted Btu calculation based on the weighted average of all gas flowing to    the system on NNG, NGPL, ANR and NBPL pipelines. Navigator Btu Factors: 2008 | 2007 | 2006 For Your Home | For Your Business | Safety | Rates | Energy Efficiency | Economic Development | Environmental Efforts About Us | Careers | News Room | Storm Center | Wind Energy | Contact | Streetlight Repair Request | System Outage Watch | Energy Choice | For Contractors | For Landlords | ©2008 MidAmerican Energy Holdings Company. All rights reserved.