Retired Army Colonel Sheri Swokowski (left), who served openly as transgender, speaks on a panel at a Navy pride month event in 2015. Earnie Grafton/Reuters President Trump announced on Wednesday a new policy barring trans people from serving "in any capacity" in the military and claiming that their service creates "tremendous medical costs and disruption."

But about one-fifth of the transgender population in the US are veterans of the military — meaning that transgender people serve in the military at approximately twice the rate of the general population, according to a 2014 report by researchers at the UCLA School of Law.

There are approximately 15,500 transgender people on active duty or serving in the Guard or Reserve forces and 134,300 veterans or retired Guard or Reserve members, according to the 2014 data.

8,800 of those serving are on active duty.

These numbers were determined by the National Transgender Discrimination Survey (NTDS), conducted by the advocacy groups the National Gay and Lesbian Task Force and the National Center for Transgender Equality, and reported in the UCLA study.

The UCLA study found that around 20% of transgender people enlist in the military, compared to around 10% for the general population.

Trans military members give a wide range of reasons for their decision to enlist, according to an LA Times article exploring the issue in 2015. Some said they joined the military with the hopes of gaining financial security and community support that they had difficulty finding elsewhere. Others said they used their military service as an escape from pressures to conform within their communities.

There is insufficient research to support any general theories about why transgender Americans disproportionately enlist.

In July 2016, former President Barack Obama lifted a ban on trans individuals from serving openly in the military. The implementation of the new policy was delayed for a year. But on Wednesday, President Donald Trump reversed Obama's decision.