How to designate the X5-(X+1)0% range?
E.g. for the 85-90% range, which one(s) amongst the following are correct, which one sounds the best, and is there any better alternatives?
- the high 80%
- the top 80%
The symbol "%" is normally pronounced "percent", not "percents". In this context, the extra "s" makes a big difference. To abbreviate "percents", you need to explicitly include the "s".
"The range between 85% and 90%" is clear. There is the usual ambiguity about the endpoints: Are they inclusive or exclusive?
"The upper 80 percents" and "the upper 80%s" are less clear, but have a similar meaning. I would expect them to mean "the range greater than or equal to 87% and less than 90%". Notice the "s".
"The top 80%" and "the upper 80%" clearly include everything from 20.01% through 100%. (Plus some wiggle room for rounding error.)
"The high 80%" is less clear, but also means everything from 20.01% through 100%. (Again, allow some wiggle room for rounding error.)
If it is clear (from the context) that you are discussing percentages, you can omit the word "percent", but you still need to keep the "s". For example:
The high 80s.
The technical way to refer to this would be a ventile. See https://en.wiktionary.org/wiki/ventile. Specifically, this is the eighteenth ventile, with the nineteenth ventile being from 90% to 95%, and the twentieth being from 95% to 100%. This is of course by analogy to other quantiles, such as percentiles and quartiles.
It should be noted that this refers specifically to quantiles in data distributions, not percentages of other quantities. So if you are describing students' scores, someone who scores 90% might be in the first ventile or the twentieth, depending on how the other students scored.