The Consumer Price Index (CPI) is a way of tracking the cost of living. It is computed based on prices for the "market basket" of necessities including housing, food and beverages, transportation, apparel, entertainment, medical care, and other goods and services. The CPI is updated monthly based on the Department of Labor surveys. To track the effects of price increases, the years 1982 to 1984 are set as a basis (equal to 100). A price index of 33, therefore, indicates that the price was one-third that of the average in 1982-1984.