William the Pukwudgie who alternatively is saved by Isolt and goes on to save her is a key character in the creation of Ilvermorny. The fact that it is rumored that William the Pukwudgie is still loyally looking over Ilvermorny long after Isolt's death seems to be a testament to this House association.
Base price definition, a price quoted as a base without including additional charges. See more.
Therefore 2005 is base period and 60$ is base price. Similarly 2006 is the current period and $80 is current price. This current price is now converted into percentage relative to the base price i.e. 80/60*100 = 133.33%. This percentage is called price relative or simple price index. The concept of simple price index can be elaborated with the help of simple problem.