When you calculate percent change, you are calculating the change in numerical values over time. Calculating change as a percentage is a form of normalization, which makes it especially useful for comparing areas that are not uniform in size or population.
Note:
You can also calculate percent change using the data table.
Example
A crime analyst is studying the effects of a city's crime reduction strategy. Calculate % Change can be used to determine the effectiveness of the strategy in different districts using the crime rate before the program started and the crime rate after the program's implementation.
Run Calculate % Change
Use the following steps to calculate percent change:
- Create a map, chart, or table using the dataset with which you want to calculate percent change.
- Click the Action button
. - Do one of the following:
- For chart and table cards, click How has it changed in the Analytics pane.
- For a map card, click the Find answers tab and click How has it changed.
- Click Calculate % Change.
- For Choose a layer, select the dataset to use to calculate percent change.
- For Choose number fields, choose the fields to use for the initial value and final value.
The fields must be a number or rate/ratio.
- For Name the result field, provide a name for the new field.
- Click Run.
A new rate/ratio field is added to the specified dataset.
Usage notes
To access Calculate % Change, click the Action button under How has it changed on the Find answers tab. The input layer can be a point, line, or area layer.
Two number fields must be specified as the initial value and the final value. The number fields are used in the (final_value-initial_value)/initial_value*100 equation.
Calculate % Change adds a new rate/ratio field to the input layer. You must include a new field name to run the calculation.