Create and use an index over time-series data

Sometimes you have to compare data that you can't compare at first glance. For example, one would like to compare the income development of two industries. In this case it is a good idea to build the index over both time series.

How to compute an index

With an index, you set the value at a given time t to 1 (or 100). All other values are now calculated in relation to this value. This procedure is now used for each time series.