As rents rise throughout the city, the number of apartments for working-class and poor New Yorkers has declined by 20 percent since 1993, according to the most recent Housing and Vacancy Survey.

The survey, which is produced every three years by the federal census bureau, shows that rents are up, renters’ incomes are down, and the number of rent-controlled units in the city is plummeting as elderly tenants die or leave them.

But it is the general rise in rents—and the proliferation of gentrified, high-end units—that is the most startling finding of the survey. Since 1993, there are 112,000 fewer apartments in New York City renting for less than $500 per month. The total number of such units has free-fallen to 452,000 in 1996, even as federal rent subsidies and the city’s commitment to subsidizing rehabs decline sharply.

"It reinforces everything we’ve been hearing anecdotally out in communities for the past few years," said Victor Bach, a housing policy researcher for the Community Service Society. "We need to do something to assure that low-income people aren’t forced out of the housing market by rent inflation."

The survey also found a boom in the luxury end of the market, with the number of apartments renting for $1,500 or more growing from 49,000 to 55,700. —Andrew White and Glenn Thrush