Credit card debt is the norm for a majority of Americans. But you already knew that, didn’t you?

A recent study conducted by the Federal Reserve Bank of Boston and cited by Bloomberg Business paints the picture. About 35% of Americans ages 25 to 50 pay off their credit card debt every month, but most of credit card debt resides with people called “revolvers,” or Americans who pay interest on their debt from carrying a monthly balance, reports Bloomberg. As of December, consumers owed a total of $936 billion in credit card and other debt, including that from auto and student loans.

The Federal Reserve Bank of Boston study analyzed a 5% sample of every U.S. credit account from 1999 to 2014 to come up with its findings, from which several trends emerge. As Bloomberg notes, most people’s credit card borrowing remains consistent over time: People who generally borrow more on their credit cards continue doing so throughout life, and those who borrow less stick to their respective habit. Although, if consumers are offered a higher credit limit by banks, they’ll borrow more.

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Perhaps the most striking, if unsurprising, finding from the study concerns a portion of the Millennial set, that age group generally characterized as being between 18 and 34. For Americans between 20 and 30, their credit card limits increase about 450% during that period of time. Accordingly, their debt also rises—by about 300%.

Those in the Millennial set might feel the burdens of debt most acutely, as some are just starting out in the job market and looking to gain a firm financial footing. About 13% of people ages 22 and 23 work in low-skill, lower wage service jobs just after graduating college, according to U.S. News. (By the time they’ve reached ages 26 and 27, that share is cut in half.) And overall, a majority of people between 18 and 34 have less than $1,000 in their savings accounts, or no savings accounts at all.

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“People in their 20s don’t seem to save much,” Scott Fulford, a Boston College professor who co-authored the recent Federal Reserve Bank of Boston study, told Bloomberg.

Fulford also offered another explanation for the high levels of credit card debt among people ages 20 to 30. Savings for people in that age group usually means obtaining a higher credit limit. As he told Bloomberg, “That provides the funds for emergencies that they need.”