Methodology and corrections

Last updated: 10 November 2026

A number is on a card only when a publisher already printed it.

Michael Yao, creator of ranki.gg, keeps the tables tied to those publishers. The sources page names which publisher sits behind each learn page. This page is the rule for what may be said about a figure, and how a wrong one gets fixed.

How a figure gets on a card

• The value, the year, and the unit come from one cited table or article. A second number is not added in the fact unless that same source states it.
• The card says what the measure is. Food supply is food available, not a weighed plate. A renewable share can be firewood. A time-zone count includes territories.
• Countries with the same value share a rank. The order on the card is the order of the values.
• A puzzle that cannot be tied to a URL is not shipped.

Corrections

If a copied figure does not match the linked source, write to mikelyaps@gmail.com. Name the puzzle, the country or the row, the figure you saw, and the publisher URL that disagrees. Corrections are applied to the card and, when that card has a learn page, to the table on that page. The date at the top of a learn page is the last time that page was edited.

Browse the explainers. About says who makes the game.