I'm currently reading an article titled "Workers anxiety in a 'gig economy'" by Noam Scheiber from International New York Times. I came across the paragraph below:
Last year, 23 percent of Americans told Gallup they worried that their working hours would be cut back, up from percentages in the low to midteens in the years leading up to the recession. Twenty-four percent said they worried that their wages would be reduced, up from the mid-to high teens before the recession.
I think it's saying people are worried that their working hours would be cut back by, say, 12 to 15 percent and their wages by 15 to 18 percent.
Then, I noticed that the the first part doesn't have a hyphen after low, and "midteens" is a one word. But the second part has a hyphen after "mid" and "high teens" are written as two words.
Can anyone explain why there is this difference and if it makes any difference in meaning, if there is?
Also, I am not very familiar with "up from" in this way of usage. It would be also nice if someone can help me with this particular phrasing.