Aluminium cans sold and recycled in Australia
Explain that when categorical data are recorded over time, time can be used as a grouping variable.
Click Stacked. Observe the trend in the total number of cans sold and the number recycled.
Choose Propn within Year. Observe how the proportion of cans that were recycled increased.
The data are the numbers of aluminium beverage cans sold in Australia between 1978 and 1989, and the numbers returned for recycling.