"Increase" or "Decrease" of Ratio

Is the second sentence below referring to an increase or decrease of the ratio?

"In 2010, the ratio was 1 out of 100. In 2013, the ratio became 1 out of 200."

A decrease from 1% to 0.5%. But that's a mathematical question, not a language question.

Alexander2 said:

"In 2010, the ratio was 1 out of 100. In 2013, the ratio became 1 out of 200."

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"In 2010, the ratio was 1 bad apple out of in 100 apples. In 2013, the ratio decreased to 1 bad apple out of in 200 apples." -> there were fewer bad apples.

Alexander2 said:

Is the second sentence below referring to an increase or decrease of the ratio?

"In 2010, the ratio was 1 out of 100. In 2013, the ratio became 1 out of 200."

Click to expand...

"1 out of 100" is not a ratio, but a proportion or a fraction, and these can increase and decrease in the English language as they can in mathematics.

If you wanted to express 1 out of 100 as a ratio, it would be 1:99 or "one to ninety-nine".

Ratios can also increase and decrease in the English language, even though this makes little sense mathematically. The first-named term is always the most important, and is the one you use (as a fraction of the whole) to determine whether "increase" or "decrease" applies:
Alternatively
Both these sentences say the same thing, mathematically.

Thank you. I did not know that the word “ratio” should not be used in instances where one quantity is said to be “out of” another quantity. The reduction of the proportion can therefore be worded in this way:

"In 2010, the proportion was 1 out of 100. In 2013, the proportion was reduced to 1 out of 200."

Alexander2 said:

I did not know that the word “ratio” should not be used in instances where one quantity is said to be “out of” another quantity.

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Sorry, I did not mean to be overly critical; you will find that many English speakers use "ratio" in exactly the way you did, and no one really worries about it. Your original sentence was grammatically correct, understandable and unambiguous. And yes, you can use "decrease".

Alexander2 said:

"In 2010, the proportion was 1 out of 100. In 2013, the proportion was reduced to 1 out of 200."

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While you might use "was reduced", this is the passive voice, which might not be what you mean. Unless you specifically want to state that an unnamed agent reduced the proportion, it would be more common to say "the proportion reduced". If you told us what the sentence described, we could say whether the active or passive voice is more appropriate.

I had invented the sentences quoted earlier myself to ask whether when the second quantity in a proportion increases, the proportion itself increases or decreases. Now I see that it decreases.

The text which I had been thinking about was the following. I had written it in another place and wanted to check whether it is correct.

“With regard to violent crimes, the safety of the population can be measured by the proportion or percentage of people affected by crimes. For example, if a certain city 200 years ago had 10,000 inhabitants but now has 1,000,000, and if 200 years ago 100 people died from violent crimes in that city each year, whereas 1,000 people die from violent crimes in the same city 200 years later—this means that the city is safer to live in 200 years later. Even though the number of people dying from violent crimes has increased in the city (from 100 to 1,000), the actual proportion and percentage have decreased ten times. (200 years earlier, 1 out of 100 people (1 percent) were killed in violent crimes in the city each year, whereas 200 years later, it is only 1 out of 1,000 (0.1 percent)).”

(I have replaced the word “ratio” with “proportion” according to what has been said on this thread.) Are there any other things which need to be changed in the text?