The CPI takes a constant basket of goods and sees how the price changes from year to year. If the price of the basket of goods increases, then there is price inflation. If the price of the basket of goods decreases, then there is deflation.
Copper and tin mainly make up bronze but other elements include phosphorus, manganese, silicon and aluminium.
By comparison, bronze is principally an alloy of copper and tin. However, bronze and brass may also include small proportions of a range of other elements including arsenic, phosphorus, aluminium, manganese, and silicon. The term is also applied to a variety of brasses, and the distinction is largely historical.