1 Total revenue of all National Football League teams from 2001 to 2015 (in billion U.S. dollars)*Total revenue of the National Football League 2001-2015. 2  National Football League average franchise value from 2000 to 2016 (in million U.S. dollars)National Football League - average franchise value 2000-2016.
There are two types of systems in organizations: closed systems and open systems. An open system interacts with its environment through giving and receiving information. Closed systems are closed off from the outside environment, and all interaction and knowledge is transmitted within the closed system only.
Closed circulatory system. Vertebrates, and a few invertebrates, have a closed circulatory system. Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities. The open circulatory system is common to molluscs and arthropods. Open circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.