A new study has polled Americans across all 50 states on whether they identify as LGBT, providing what may be the first accurate estimates of what proportion of the population is gay, bisexual, or transgender.

The Gallup survey polled over 206,000 people in every US state plus Washington DC over a period of six months, asking: “Do you, personally, identify as lesbian, gay, bisexual, or transgender?”

The results found a nationwide average of 3.5% of the population saying they identified as LGBT. North Dakota had the lowest number of LGBT respondents at 1.7%, while Hawaii had the highest at 5.1%.

4.6% of African Americans Identified as LGBT, along with 4% of Hispanics, 4.3% of Asians and 3.2% of Caucasians.

Washington DC, the US capital city and its own district separate from any state, had the highest proportion of LGBT people, accounting for 10% of the population.

Despite the high density of LGBT respondents in the capital city, researchers said that overall the results defied stereotypes that LGBT people tend to live in cities rather than rural areas, showing a fairly even spread across the states.

Researchers said that although no state ranged more than two percentage points above or below the average, the fluctuation did correspond generally with the level of social acceptance of LGBT people. States with laws supporting LGBT people tended to have a slightly higher percentage of respondents claiming to identify as LGBT.

Every state with an LGBT population above 4% had laws prohibiting discrimination based on sexuality or gender identity, except for South Dakota.

Analysts have pointed out that this may be as much to do with willingness to self-identify as LGBT as with the actual dispersal of LGBT people, as respondents in more liberal states may have been more willing to identify that way.

“As a group still subject to social stigma, many of those who identify as lesbian, gay, bisexual or transgender may not be forthcoming about this identity when asked about it in a survey,” said researchers.

When interim findings were published in October, Demographer Gary Gates said: “Contemporary media often think of LGBT people as disproportionately white, male, urban and pretty wealthy.

“But this data reveals that, relative to the general population, the LGBT population has a larger proportion of non-white people and clearly is not overly wealthy.”

The poll claims to be the first of its kind in terms of scale and thoroughness. Previously, estimates of the LGBT population in the US had ranged from 1% to 30% of the total.

Another recent Gallup poll found that roughly the same number of LGBT Americans believe that homophobic discrimination remains a serious problem, and that people have none-the-less become more accepting in recent years.