Though the U.S. has cleared through millions of underwater mortgages, a shocking number of Gen X mortgage holders are still underwater.

Seventeen percent of the nation’s homeowners – aka 8.7 million – are still underwater on their mortgages, but one specific generation of homeowners boasts a negative equity rate far beyond the national average.

That would be Generation X, which, according to new research from Zillow, still accounts for an incredible 42.6 percent of all underwater homeowners.

Stan Humphries, the chief economist for Zillow, said that the negative equity level for Generation X homeowners not only constrains housing inventory, but also the housing prospects of Millennials.

“But as this huge generation begins to consider buying homes, they’re entering a market still very much in recovery and far from anyone’s definition of normal,” Humphries said. “Because so many homes are stuck in negative equity or are effectively underwater, the inventory of homes for sale is severely constrained, leading to more competition for those that are available. And Millennials likely don’t have the resources to compete with cash offers or engage in bidding wars. The reality is, negative equity is part of the new normal, and finding creative solutions to keeping homes affordable, available and accessible to this generation will be critical going forward.”

Generation X, though, is not the only generation with negative equity problems; as our graph below shows, in terms of total homeowners in each generation, Millennials have a larger share of underwater homeowners than Gen X: