describe charts: "the numbers/percentages of" or "the number/percentage of"

When describing the chart, should I use "the number/percentage of" or "the numbers/percentages of" in this sentence? Thanks for your kind help.

(1a) The bar chart illustrates the number of museums and museum visitors from 2020 to 2022. (1a) The bar chart illustrates the numbers of museums and museum visitors from 2020 to 2022.

(2a) The bar chart illustrates the percentage of divorce rates in Finland and Sweden. (2b) The bar chart illustrates the percentages of divorce rates in Finland and Sweden.

In both of your examples, the answer is plural because there are two different numbers and two different percentages for each year in the charts.

That's to say, even if you break it down by year, there's still more than one number or more than one percentage, so the answer is definitely plural.

If there were just one number (say, museum visitors only) or just one percentage (say, divorce rate in Finland only), but it was still spread out over several years, then it's arguable whether to use singular or plural.

The argument for singular is that it's a single variable that changes over time, and the chart follows this one variable. The argument for plural is that the variable has a different value in each year, and the chart compares these different values.

There may be a recommended way to handle this situation for standardized English exams, but I don't know what it is.

You didn't ask, but it's worth noting that you cannot talk about "the percentage" of a rate. A percentage IS a rate. So either talk about the "percentages of divorce" OR talk about the "rates of divorce". "Rates" of divorce happens to be idiomatic, and it's already phrased that way in the question, so best to choose "rates of divorce".

• Thanks for your detailed answer! Commented Dec 1, 2022 at 2:47
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– gotube
Commented Dec 1, 2022 at 3:57
• Excuse me. I don't know how to send a private message. Will you please check another question concerning chart description? ell.stackexchange.com/questions/328330/… Commented Dec 1, 2022 at 8:30
• @gotube, do you know why this chart (snipboard.io/kyq7Ut.jpg) uses "percentage" and not "percentages"? After reading your answer, I think "percentages" should be used. Commented Dec 25, 2022 at 14:24