We all know that figures can vary widely from various publications, and usually precise figures are irrelevant.
Some texts favor listing the range that has been published without giving a 'best guess ballpark figure'. We feel this is not entirely useful as it often generates very wide ranges which are hard to remember and are of little help: e.g. 5-72%
When you encounter such a problem please try and collapse the figures to a rough average that agrees with most of the figures and includes the range as well, with appropriate references. Text books have done this often, using multiple sources to arrive at a ball-park.
The resulting number should look like: ~35% (range 12-72%) 1-5.
Note the following structure:
- ~ indicates that this is an approximation (this symbol is technically known as the tilde)
- occasionally a double tilde '≈' is used, with more precision than with a '~'
- when the '~' or '≈' is used, there should not be a space after it, e.g. "~15"
- figure is rounded off
- to nearest 5 for numbers between 15-85% is usually appropriate
- at either extreme precise numbers are probably best
- the range is in brackets
- references included to support this range