Yes, a cumulative sum would have done a much better job than that pie chart at illustrating their point (from the text: "Apple over the last four years spent mo

Yes, a cumulative sum would have done a much better job than that pie chart at illustrating their point (from the text: "Apple over the last four years spent more on R&D than it did during the preceding 15 years combined") Also note that 'time series' is a well-defined and widely-used term that exactly describes the dataset presented here (http://en.wikipedia.org/wiki/Time_series http://en.wikipedia.org/wiki/Time_series).