Any increase is passed on to the customer, and any decrease is shown as a credit on the bill.
The City only passes on the increase with no markup. Like other commodities, such as wheat and orange juice, natural gas prices rise and fall as supply and demand change. Supplies of natural gas are tight temporarily, which has led to higher prices. The United States has enjoyed a strong economy for the past 7-8 years. As a result, demand for all forms of energy has increased.