Martha’s Vineyard renters and mortgage-holders are under extraordinary financial pressure, with a majority shelling out more than 30 per cent of their household income on housing, new figures from the U.S. Census Bureau show.

Census figures based on samples taken from 2005 to 2009 were released on Tuesday. The numbers take in both boom and bust years in the American economy, suggesting they may spruce up the worst of the recession’s effects.

Yet they show that more than half — 57 per cent — of Island renters have been spending about a third of their incomes to pay for their shelter. Ten years ago, only about one in four renters here faced the same comparative housing burden.

The numbers add more weight to comments made recently by Dukes County Regional Housing Authority executive director David Vigneault, who said what he is seeing “is not a difference by degree, it’s by type . . . renters who always managed to patch it together, aren’t able to patch now. Two, three years into the recession, there are no more margins, they can’t find any new ways.

“This is watershed stuff,” Mr. Vigneault said.

Renters nationwide are struggling, although not quite to the same extent, with half of American renters devoting so much of their incomes to housing costs.

The figures are included in the single largest data release in the Census Bureau’s history. Part of the American Community Survey, which replaced the long-form census, this week’s numbers provide a look for the first time since 2000 at a variety of characteristics, including population, income, race, immigration and housing.

On the Island the burden for homeowners with a mortgage was almost as heavy as it was for renters, with 56 per cent spending 30 per cent or more of their money on housing.

This majority of mortgage-holders struggling here compares to just over a third of homeowners with a mortgage nationwide who direct so much of their income to housing costs.

Even Island homeowners without a mortgage are finding that housing costs are eating up a third of their incomes — one in three who own their house outright pay that much here, a dramatically larger proportion than the country as a whole, where only 15 per cent of homeowners are in the same situation.

Perhaps unsurprisingly, then, the figures show that Island parents are becoming two-income families at an increasing clip, and while their children are younger. In 2000, about 57 per cent of Island children under six had both parents in the labor force, while now the figure is 87 per cent.

However, the Census Bureau cautions that the margin of error for such a small sample — there are but 1,000 children under six in the county — can be up to 14 per cent. Yet the economic squeeze is evident throughout the numbers.

The Vineyard’s furious growth of the 1980s and 1990s has slowed, with the Dukes Country population up only about six per cent in the past 10 years — to almost 16,000 — compared to nearly 29 per cent growth in the 1990s.

Still, construction accounted for 18 per cent of Dukes County employment for the period 2004 to 2009, compared to seven per cent nationwide.

The Vineyard’s 16,000 “housing units” are overwhelmingly single-unit houses (91 per cent), with multi-unit structures making up five per cent of the Island’s housing stock and mobile homes four per cent.

And they are mostly — 65 per cent — vacant.

A quarter of the Island’s homes were built in the 1980s, 18 per cent were built in the 1990s, and less than four per cent since 2000.

Home values in some Island towns ranked with the highest in the nation; the median home value in both Chilmark and Aquinnah was over $1 million (the survey does not distinguish prices above a million). The lowest median home value of the six Island towns was in Tisbury, where it was just under $600,000.

Yet per capita income in Dukes County is pretty much the same as that across Massachusetts, around $33,500. American per capita income in 2005 to 2009 was just over $27,000.

But the disparity between Vineyarders’ median and mean household income shows how high-income earners here skew the figures substantially.

The median shows where most peoples’ income — earnings, retirement benefits and Social Security — cluster; the mean is the average of all residents’ income. For example, if five people live in town and four of them make $100 while one makes $600, the median would be $100 but the mean, or average, would be $200, twice what most people actually make.

The average household income in Dukes County is about $83,000. But the median is much lower, at about $62,500.

The gap is greatest in Chilmark, where average household income is over $150,000, while the median household income is just under $83,000.

Most people in Tisbury, Oak Bluffs and Aquinnah have a household income around $70,000, and the mean, or average, income is about the same. In Edgartown and West Tisbury, most households take in $70,000 to $75,000 while the average in both towns is closer to $90,000.

The survey counted 5,600 households in Dukes County, 64 per cent of them families. Some 28 per cent of those households are people living alone.

Fewer people live in poverty on the Vineyard and Cuttyhunk, also included in Dukes County, than in the nation at large; in 2005 to 2009 eight per cent of people here were in poverty while 14 per cent of Americans were.

Eleven per cent of people living in Dukes County in 2005-2009 were foreign-born, about the same proportion as the nation overall. More than half the foreign-born Vineyarders came from Latin America; nearly 20 per cent came here from Europe and 11 per cent from Asia.

This is a notable change from 1990, when foreign-born folks barely registered in the Island census. Ten years ago, Vineyard residents born overseas accounted for about six per cent of the Island population. In Tisbury foreign-born residents make up 21 per cent of the population, and in Oak Bluffs, 13 per cent.

Nationwide, one in five Americans age five and older speak a language other than English at home; in Dukes County, it is one in 10.

Of those in the county who do speak another first language, about one third reported not speaking English “very well,” while nationwide a much higher proportion — 44 per cent — had trouble speaking English “very well.”

Across the country, Spanish is by far the most common primary language after English, but it accounted for only three per cent of the non-English speakers here, where 97 reported “some other language.” Portuguese was not among the choices.

Island towns are among the most educated in the country. In fact Chilmark, where 69 per cent of the population age 25 and older has a bachelor’s degree or higher, was only narrowly edged out by Falls Church, Va., which led the country with 69.5 per cent.

Overall, 40 per cent of Dukes County adults had college degrees, compared to 27.5 per cent of Americans.

The Island town with the oldest median age was West Tisbury, at 48.3 years old, and youngest in Oak Bluffs, at 38.8.

Twenty per cent of the Dukes County population was under 18 years and 15 per cent was 65 years old or older.