Seattle City Light 2016 ANNUAL REPORT | Supplementary Information 88 CUSTOMER STATISTICS (Unaudited) Kilowatt hours used (in billions) Number of customers (in thousands) 2012 2013 2014 2015 2016 2012 2013 2014 2015 2016 RESIDENTIAL CONSUMPTION Kilowatt hours used (in billions) Number of customers (in thousands) NON-RESIDENTIAL CONSUMPTION * Note: Source of national data: Department of Energy (www.eia.doe.gov/electricity/annual/). 2016 National average annual consumption data and average rate data not available; Certain 2015-2012 National average annual consumption and National average rate data were updated with revised actuals. Effective 2013, allocation of net change in unbilled revenue excludes retail customer voluntary payments for conservation and solar energy. Prior years presented were not revised. Average Customers Kilowatt hours used Average Customers Kilowatt hours used 2.90 2.95 3.00 3.05 3.10 3.15 3.20 360 360 370 370 400 400 6.20 6.25 6.35 38 40 52 2012 2013 2014 2015 2016 AVERAGE ANNUAL RESIDENTIAL CONSUMPTION* (in thousands of kilowatt hours) Seattle National AVERAGE RESIDENTIAL RATES Seattle National AVERAGE ANNUAL NON–RESIDENTIAL CONSUMPTION Seattle National AVERAGE NON–RESIDENTIAL RATES (in cents per kilowatt hour) Seattle National (in cents per kilowatt hour) (in thousands of kilowatt hours) 0 3 6 9 12 2012 2013 2014 2015 2016 0 2 6 8 14 0 50 100 150 200 2012 2013 2014 2015 2016 0 2 4 6 8 10 2012 2013 2014 2015 2016 380 380 390 390 10 4 46 6.40 6.30 48 42 44 50 12