This story is part of a series on how Philadelphia is changing as reflected in the new 2010 census figures.

JOSH PARK and his boyfriend lived near the city's Gayborhood, by 10th and Locust streets, for three years until moving to Society Hill in June.

"Everything's pretty close - the restaurants, the gay bars in the area," and it's close to public transportation, Park, 33, a physician's assistant at Thomas Jefferson University Hospital, said of the reasons why they moved into Center City.

Park and his boyfriend are one of the 4,800 same-sex-couple households in the city last year, according to revised census estimates being released today by the Williams Institute at UCLA's School of Law. That represents 0.8 percent of the city's 599,736 households; some in the gay community believe it is low.

"We expected an undercount - absolutely," Mark Segal, publisher of the Philadelphia Gay News, said yesteday. "Do you trust your government to have that information [whether someone is gay] in a time when there is discrimination? Unfortunately, people don't trust their government."

Segal estimated the number of gay- and lesbian-couple households in the city to be four times more. The same-sex-household data include only those couples in which one partner owns or rents a residence. The data do not include couples living in the house of another householder or single gay men or lesbians.

Segal believes the total number of gay people has remained stable in the city over the past three decades, pointing to poll data that have shown about 25,000 city voters are gay or lesbian .

The revised household statistics are based on revised Census Bureau data released last week at the state level. The bureau said earlier that counts released over the summer were found to have been artificially inflated because of how the question was asked on the 2010 census form.

Based on the revised data, the number of same-sex-couple households in Pennsylvania spiked 120 percent from 10,000 in 2000 to 22,000 last year.

Gary Gates, a demographer at the Williams Institute, said the "jump is largely an indication of a willingness of same-sex couples to report," and not an indication that more gay couples suddenly decided to move here.

"Places that have larger jumps" are "more socially conservative" like Pennsylvania, he said.

Based on the revised Williams figures, the highest percentage of same-sex-couple households are in Center City, Society Hill, South Philly around Passyunk Avenue, Southwest Center City and West Mount Airy.

Ed Hermance, owner of Giovanni's Room, an LGBT bookstore at 12th and Pine streets, said Center City has become more attractive to gays and lesbians because "they feel safe."

Hermance, 71, single and gay, lives in Powelton Village, where the "activist sorts" of gay men have lived since the early 1970s, he said.

Meanwhile, Mount Airy and Germantown have attracted lesbians in the past 20 to 30 years as homeowners, he said.