Sources and methods

Our method

1. Primary sources only. A figure appears on this site only after we have read it on the publisher's own page or document: a regulator, a government statistics office, an international organisation, a professional association, a research publisher or an event organiser.
2. One citation per figure. Each number carries a numbered citation linking to that page, with the publication or update date.
3. No estimates. Where a figure is not published, we say so. We do not fill gaps with estimates or numbers from aggregator websites.
4. Forecasts are attributed. Market forecasts are labelled with the publisher, base year and forecast year. We do not average different publishers' figures.
5. Dates are checked on organiser sites. Event dates come from the organiser's own website, and past editions are marked as held.
6. Regular review. Pages are reviewed when a source publishes an update, and at least once a year.

All sources

Corrections

If you believe a figure is out of date or wrong, please contact us with the page, the figure and the newer source. We will check it on the publisher's page and update the citation.