Imagine that the government decided to fund its current deficit of $431 billion dollars by issuing a perpetuity offering a 4% annual return. How much would the government have to pay bondholders each year in perpetuity? Express your answer in billions of dollars. (Hint: The $431 billion is just the present value of these cash flows at a discount rate of 4%.) *Make sure to input all currency answers without any currency symbols or commas, and use two decimal places of precision.