# What word would you use to describe this figure: "20 per 1000 people"? A proportion?

Whenever I encounter figures in sentences like:

"The number of artists in this city is 20 per 1000 people."

I just don't know what word to use. In my mother tongue, there's a very specific word which describes this kind of figure, but I'm not sure what's the equivalent English term.

So, what word can replace "number" in this situation?

• Yes, I believe "proportion" is the best choice for expressing that concept in a general context, like in your artists example. There is a very specific word in English which often goes with expressions like "20 per 1000 people," but its use seems to be restricted to the field of epidemiology (the study of diseases). This is prevalence, as defined here: en.wikipedia.org/wiki/Prevalence "[T]he proportion of a particular population found to be affected by a medical condition." You can see the discipline-specific term is actually defined using the more general "proportion." Commented May 15 at 5:33
• Where have you encountered sentences such as that? Not likely. Commented May 15 at 13:37
• @QuackE.Duck I suggest writing this as an answer because the discipline-specific term is important context.
– qwr
Commented May 15 at 16:12
• This is orthogonal to the question, but unless there was a surrounding discussion that involved tracking things per thousand people, I would probably simplify this to ‘2 per 100’ or even ‘1 per 50’ (or ‘1 in 50’, which sounds a bit more natural). No matter the language, people have an easier time thinking in terms of smaller numbers, so simplifying this can help (sometimes significantly) with understanding. Commented May 15 at 20:52

There you are expressing a proportion.

A proportion is "the relation of one part to another or to the whole with respect to magnitude, quantity, or degree".

Here we are speaking of "part" to "whole", artists to overall population. (The proportion is expressed via an arbitrary easy-to-work-with denominator, 1000.)

[“Proportion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/proportion. Accessed 15 May. 2024.]

• But rate is, in some contexts, as well suited or better suited. Commented May 15 at 13:15
• Though I don't think it is idiomatic to speak of the "rate of artists". Gotta improve the artist rate, Paducah.
– TimR
Commented May 15 at 13:32
• Agreed, it wouldn’t fit in this context without a bit of reworking. Commented May 15 at 13:35
• It's beancounterish. What was the love-at-first-sight rate in Q3?
– TimR
Commented May 15 at 13:36
• Yes, but some contexts do call for beans to be counted. An example would be a report on census data by locale and occupation. Commented May 15 at 13:46

In chemistry and biology specifically, standard abbreviations are ppm (parts-per-million) and ppb (parts-per-billion). Parts-per-thousand has a special word "permille" and symbol ‰, but these are pretty uncommon. These terms wouldn't be used for proportions of people, as "parts" is used for inanimate objects.

• Just to state the semi-obvious explicitly, "permille" is analogous to the far-more-common "percent", and ‰ is analogous to %. Commented May 15 at 20:11

This phrase can also be described as a ratio. A ratio is a quantitative relation between two numbers that represent how many times one number goes into the other. A ratio is formatted as follows, 20:100.

• I'd thought so but after searching for relevant posts in the forum, I found that people were divided on the use of ratio in this situation. See this Commented May 16 at 1:39
• I don't read "20 per 1000 people" as a ratio at all, "per" implies the 20 are part of the 1000. The ratio "20:1000" would be "20 per 1020".
– DBS
Commented May 16 at 14:56
• @DBS Some rations (such as odds ratios) work that way but not all do. You can have a ratio X:Y where X measures a part of something and Y measures the whole thing. It happens in geometry all the time. Commented May 16 at 22:47

As @TimR has confirmed, "proportion" really is the best choice for a word that describes the concept X per Y people (where X and Y are numbers) in a general context.

It is probably the best replacement for "number" in sentences like your example:

"The number (proportion) of artists in this city is 20 per 1000 people."

However, there are more specific terms which are often associated with the same kind of phrase (X per Y people) in certain discipline-specific contexts.

One of these is "prevalence."

Prevalence is defined (by Wikipedia) as "[T]he proportion of a particular population found to be affected by a medical condition." It is the standard way of expressing the concept within the field of epidemiology (the study of diseases and their spread, from a statistical perspective).

A closely related (and easily confused) term is "incidence," which refers exclusively to new cases within a certain timeframe. Here is a source (Data Literacy.com) which compares/contrasts both words' definitions.

@qwr has provided some other examples of specific terms that express the idea "X per Y" within the fields of biology and chemistry. Note that these do not require the numbers X and Y to refer to people.

• I think you can use "prevalence" for artists too, but I'm not 100% sure.
– qwr
Commented May 15 at 20:22

"The number of artists in this city is 20 per 1000 people."

1 artist per 50 persons is a rate. Other examples of rates are

• literacy rates
• exchange rates
• speeds.

Here, the relative frequency or prevalence of artists in the population is 2%.

1 artist per 50 persons is sometimes called a “proportion” to mean that the fraction of artists in the population is 1/50. Technically, though, a proportion is a quantitative comparison of ratios (for example, two variables being in proportion means that their values are in a fixed ratio).

1 artist per 50 persons is certainly not a ratio, which is an object like 1 artist to 50 persons or 1 artist to 49 non-artists.

I do not think there is a good word for this. I think it sounds much more natural to avoid the term and say:

Twenty of every thousand people in this city are artists.

Or,

There are 20 artists for every 1000 people in this city.

I agree with others that the words rate, proportion, or prevalence could be used, but none of these sound natural to me.

Alternately, expressing it as a percentage would be quite common:

Artists make up two percent of the population in this city.

Or,

Two percent of this city are artists.

I tried looking up Bureau of Labor Statistics publications, assuming they'd have some term for "the number of people in a particular profession per 1000 people" -- or at least something similar. I found that they almost always use percentages in body text, then they display the total numbers in tables. I did find one publication where they list the number you're talking about, but they just call it "employment per 1000 jobs"; they don't appear to have a distinct term for it.