Index Value Plot

An Index Value Plot is a geovisualization that plots an index value rather than an absolute number. An index value is determined and then the values for subsequent periods are divided by the initial average and multiplied by 100, so that all of the plots values are relative to the index value. A common index used in economics is the market basket known as the basket of consumer goods, used to define the Consumer Price Index. The accompanying index value plot indexes home values using a benchmark value from 1890 and factoring out inflation. It shows the high of the housing value boom in the early years of the 21st century.