Wikipedia:Numbers need citations

"Sixty-three percent of all statistics are made up on the spot."

- Anonymous

Overview
In order to uphold and enhance the reputation of Wikipedia as a credible academic reference point, every effort should be made to ensure that all facts and figures discussed in Wikipedia articles are well sourced, and can stand up to scrutiny.

Numerical figures in all circumstances -- whether statistics, population numbers, geographical or economic data, or otherwise -- require citation whenever they are not self-evident. And, more often than not, they are not self-evident.

As a general rule of thumb, any numerical figure or claim not backed up by a reliable source is essentially meaningless.

How to help
There are many simple actions that you, as a Wikipedia editor, can take to ensure that every number is properly cited:


 * When creating a new article, always cite your numbers. If you have a numerical figure you believe to be accurate, but which you cannot support with a credible outside source, omit it, or mark it with a citation needed, cn, or fact tag.


 * When editing articles, tag any numbers or statistical claims that you notice to be unsourced.


 * Assume that any numbers given in an article -- whether of your creation or someone else's -- are not self-evident, and are not common knowledge. If even the slightest doubt can be cast by an impartial reader upon a given figure, it must be sourced.


 * Make sure that your citations refer back to reliable, up-to-date, and unbiased publications or broadcasts.


 * Try to replace weasel words in articles with credible numbers or facts whenever possible.