Bar or Column charts are often used to present the same kinds of data as pie charts, but bar charts can include multiple series as opposed to the single series shown in Figure 1-4. In Figure 1-5, data for three periods is presented, but the detail of each entry has been eliminated. For analysis purposes, it is possible to determine the general trends for each country, but not the precise numbers. This will be effective in some situations; in others, it may be necessary to supplement the display with the actual