How to read the numbers.
Clear definitions, visible reference years, and no invented observations.
One source per statistical series
All seven global indicators use the World Bank Indicators API v2, World Development Indicators. Wikidata supplies country information only. KOSIS will provide a separate Korea-only section; it never replaces global comparison values.
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 shows each country’s latest observation and year. Differences (A − B) and ratios (A / B) are calculated in the most recent year with non-null values for both countries; that year and its operands are shown. Without a common year, no difference or ratio is reported. Ratios are limited to population and GDP indicators, require a positive denominator and a nonnegative numerator, and are never shown for inflation. Percentage indicators use percentage-point differences.
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 inflation and unemployment it is the difference in percentage points. GDP and GDP per capita use current US dollars, not constant prices or purchasing-power parity; exchange rates and inflation can affect trends.
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.