A new poll has found that more adults identify as lesbian, gay, bisexual or transgender than ever before.
According to a Gallup poll released Wednesday, 5.6% of United States adults identify as LGBT. That's up from 4.5%, based on the company's 2017 data. In 2012, when Gallup began tracking the measure, that number was 3.5%.
For the first time, Gallup also asked respondents to indicate their precise sexual orientation, as opposed to responding "yes" or "no" to whether they identify as lesbian, gay, bisexual or transgender.
The poll found that more than half of LGBT adults (54.6%) identify as bisexual, about a quarter (24.5%) as gay, 11.7% as lesbian and 11.3% as transgender. An additional 3.3% used a different non-heterosexual term to describe their sexual orientation, such as queer or same-gender-loving. Respondents could give multiple responses, bringing the total to over 100%.
Notably, the generational group that has the highest percentage of people who identify as LGBT is the youngest -- Generation Z (born 1997 to 2002) -- with 15.9%. That compares to 9.1% of millennials (born 1981 to 1996), 3.8% of Generation X (born 1965 to 1980), 2% of baby boomers (born 1946 to 1964) and 1.3% of traditionalists (born before 1946).
"One of the main reasons LGBT identification has been increasing over time is that younger generations are far more likely to consider themselves to be something other than heterosexual," Gallup said.
Most Gen Z adults who identify as LGBT say they are bisexual (72%), the poll found. That would mean 11.5% of Gen Z adults in the U.S. are bisexual, Gallup determined.
The increase in the nation's LGBT population was not surprising to Samantha Johnson, event manager of youth-focused events for NYC Pride, which organizes one of the largest annual pride marches in the world.
"We're breaking generational curses" like homophobia within the household and schools, Johnson told ABC News. "The visibility within media and events like NYC Pride -- these are all contributing factors to these numbers."
Johnson has witnessed firsthand a growing enthusiasm among LGBT youth. In 2017, NYC Pride began hosting Youth Pride, geared toward those ages 13 to 24, as part of its monthlong Pride festivities. That first year brought out 1,500 people, she said. The following year, there were 3,000. In 2019, the free event moved to Central Park, where more than 10,000 people attended.
Last year's NYC Pride was canceled due to the coronavirus pandemic, but Johnson is working on hosting Youth Pride virtually this year on June 26.
"We are here to provide a safe space for this generation to pass on to the next generation," she said.
MORE: LGBTQ community sees severe impact from COVID-19 pandemic, study findsThe latest Gallup poll results were based on more than 15,000 interviews conducted in 2020 with Americans ages 18 and up and may be an underestimate due to "older Americans not wanting to acknowledge an LGBT orientation," it said.
"This poll confirms what we have long known -- that the LGBTQ community is powerful and a growing force in the United States, and around the world," Human Rights Campaign President Alphonso David said in a statement. "Young adults, in particular, feel empowered to publicly claim their identities -- a compelling finding and validation for the past generations of LGBTQ advocates who have long fought for full equality."
MORE: OPINION: History shows us why the fight for LGBTQ equality is far from overAmid the findings, David called on Congress to pass the Equality Act "to secure consistent and explicit anti-discrimination protections for LGBTQ people across all areas of life."
The comprehensive legislation, which the Congressional Equality Caucus introduced in the House last week, protects LGBT people from discrimination in the workplace, housing, service and public accommodations.
President Joe Biden has also called on Congress to pass the bill. "No one should ever face discrimination or live in fear because of who they are or whom they love," he said in a statement.
ABC News' Tony Morrison and Robert Zepeda contributed to this report.