No aggregate is calculated if missing data account for more than one-third of the value of weights in the benchmark year. In a few cases the aggregate ratio may be computed as the ratio of group totals after imputing values for missing data according to the above rules for computing totals. In a few cases growth rates may be computed from time series of group totals. Growth rates are not calculated if more than half of the observations in a period are missing. For further discussion of methods of computing growth rates see below.
Aggregates denoted by an m are medians of the values shown in the table.
No value is shown if more than half of the observations for countries with a population of one million are missing. Exceptions to the rules occur throughout the book. Depending on the judgment of World Bank analysts, the aggregates may be based on as little as 50 percent of the available data. In other cases, where missing or excluded values are judged to be small or irrelevant, aggregates are based only on the data shown in the tables. Growth rates Growth rates are calculated as annual averages and represented as percentages.