Basics

Since its discovery many facts have been discovered about helium.  Approximately 11.3 percent of all elements in the universe are helium making it the second most abundant element in the universe, the first being hydrogen.  99.9% of all atoms in the universe are helium and hydrogen.  On Earth, helium is the 6th most abundant gas, making up approximately  0.000524% of the air.    

Helium can be extracted from liquid air, which is a very deficient, or along with natural gas in reservoirs below the Earths surface.  Helium comes to the surface along with the natural gas and is extracted from the natural gas by lowering the temperature to remove the then  liquefied natural gas.  Approximately 80% of the world's helium is in the US and once this helium gathered from these reservoirs was stored in large natural caves where it was used for US departments and administrations, but no longer is it kept as so and the US is selling its reserves.