Why missing data matters
A missing value means the source has no figure for that place and year, not that the figure is zero. Anthrotempo shows gaps as gaps, never fills them in silently, and does not compare two values when one of them is missing or too far from the year asked for.
Missing is not zero
If a country has no literacy figure for a year, nobody measured literacy there that year. Treating the gap as 0 % would turn a lack of measurement into a statement that nobody can read. On Anthrotempo, a missing value shows as a dash or as “no value”, and charts break the line instead of drawing it down to zero.
Gaps in time
Some series start late. The World Bank series of internet use for the world starts in 2005, and for most countries in the 1990s. A comparison with your birth year is only possible if there is a value close enough to it. The site uses the closest earlier value within five years, labelled with its own year, and otherwise says that there is nothing to compare with.
Gaps between places
Not every source covers every country and area. Some small territories have population estimates from the UN but no development indicators, and the UNDP covers 193 countries. Each source page lists the places it covers, and maps and tables leave the others blank rather than guessing.
Projections are not observations
Future years are UN projections, not data that is missing and filled in. They are labelled wherever they appear. Development indicators have no projections on the site, so future years show none.
Last updated 26 October 2026