What is the capacity of a 918′ long 2 ½” schedule 40 natural propane line, a pressure of 11″ water column, .5″ drop and a gas specific gravity of 1.50?

What is the capacity of a 918′ long 2 ½” schedule 40 natural propane line, a pressure of 11″ water column, .5″ drop and a gas specific gravity of 1.50?