Transgender
One effort to quantify the population gave a "rough estimate" that 0.3 percent of adults in the US are transgender, overlapping to an unknown degree with the estimated 3.5 percent of US adults (1-in-30) who identify as LGBT. More recent studies released in 2016 estimate the proportion of Americans who identify as transgender at 0.5 to 0.6%. This would put the total number of transgender Americans at approximately 1.4 million adults ().
Demography of the United States
The 2000 U.S. Census counted same-sex couples in an oblique way; asking the sex and the relationship to the "main householder", whose sex was also asked. One organization specializing in analyzing gay demographic data reported, based on this count in the 2000 census and in the 2000 supplementary survey, that same-sex couples comprised between 0.99% and 1.13% of U.S. couples in 2000. A 2006 report issued by The Williams Institute on Sexual Orientation concluded that the number of same-sex couples in the U.S. grew from 2000 to 2005, from nearly 600,000 couples in 2000 to almost 777,000 in 2005. A 2006 UCLA study reported that 4.1% of Americans aged 18–45 identify as gay, lesbian, or bisexual.