How to read the numbers.
Clear definitions, visible reference years, and no invented observations.
One source per statistical series
All 17 global indicators use the World Bank Indicators API v2, World Development Indicators. Wikidata supplies country information only.
Countries, economies and identifiers
We use the World Bank country catalog, excluding entries marked as aggregates (region ID NA), including regional and income groups and World. Country pages also include separately reported territories and economies. Channel Islands, a combined geography without an ISO country code, is excluded. ISO Alpha-3 is the primary identifier, with the World Bank exception XKX (XK) for Kosovo. Wikidata may use XKS; matching uses ISO3 first and a unique ISO2 fallback.
Latest does not mean the same year
Latest means the newest non-null observation in each country’s series. Reference years can differ across countries and indicators and are always displayed. Sorting latest values is not a same-year ranking. Source estimates remain source estimates; dat2ool does not create new estimates.
Missing values stay missing
Null values are never replaced by zero. Charts break at null observations and omitted years. The default chart window is the last 20 calendar years of the stored series; the full available history from 1960 can also be viewed. Values are rounded for display, while JSON retains source precision.
Comparing like with like
The comparison table uses the most recent year with non-null values for both countries for each indicator. Both country values, differences (A − B) and ratios (A / B) use that same reference year, shown beside the values. Without a common year, no comparable observation is reported. Ratios are available for population, GDP and GDP per capita (including PPP), with a positive denominator and nonnegative numerator. Percentage indicators, including growth rates and shares, use percentage-point differences (pp) and do not show ratios.
Change and economic interpretation
Year-on-year change requires observations in consecutive years. For level indicators it is (latest − previous) / |previous| × 100, undefined when previous is zero. For all percentage indicators it is the percentage-point difference, including changes in growth rates. GDP and GDP per capita in current US dollars are nominal measures affected by inflation and exchange rates. GDP growth uses constant-price data. GDP per capita, PPP uses current international dollars to account for purchasing-power differences; it is not personal income or a constant-price series.
Country information has its own limits
Wikidata metadata uses highest-ranked statements, excluding ended or future statements. Multiple capitals, currencies and languages are retained; geographic and role qualifiers are shown in parentheses. Area uses whole-area statements in square kilometers and the latest stated date when available. Conflicting equally ranked area values and ambiguous coordinates remain unavailable. Country information is currently shown in source English labels, alongside bilingual country names.
A validated daily snapshot
A scheduled job checks sources once a day. It collects data, normalizes it, writes a temporary snapshot and validates the entire dataset before replacement. An API or validation failure preserves the previous published files. No source APIs are called by site visitors. Identical source values preserve the existing snapshot timestamps, so those timestamps describe the published data rather than the latest attempted check.