- JohnLv 71 十年前最愛解答
A permille or per mille (Latin, literally meaning 'for (every) thousand') is a tenth of a percent or one part per thousand. It is written with the sign ‰ (Unicode U+2030)., which looks like a percent sign (%) with an extra 0 at the end. It is a stylized form of the three zeros in the denominator.
1‰ = 10-3.
For instance, 5‰ = 5/1000 = 0.005 = 0.5%
Examples of common use are:
Blood alcohol content
Seawater salinity. Eg "the average salinity is 35‰".
Birth and death rates.
When used to describe property taxation in the U.S., it is called the millage rate.
 Related units
Percent (%) 1 part in 100.
Basis point (‱) 1 part in 10,000.
Parts per million (ppm).
Parts per billion (ppb).
Parts per trillion (ppt).