The little data that exist on how often LGBT Americans are victims of crime could be further reduced if the U.S. Department of Justice gets its way with a request made this week.

The department says 16- and 17-year-olds should no longer be asked about their sexual orientation or gender identity in the National Crime Victimization Survey, which measures trends in whether people of a certain race, age, sexual orientation — or other identifying feature — are experiencing more or less crime.

The survey "provides crucial data on criminal victimization of LGBT people, who are subject to high rates of hate crimes and other violence," Adam P. Romero, a scholar of law at the UCLA School of Law, said in a statement slamming the proposal. Romero said the Justice Department "seems to want to bury its head in the sand."

Other critics say it's another sign the Trump administration is moving away from protecting the LGBT community. Here is what you should know about the survey and the debate:

What is the National Crime Victimization Survey?

The federal government calls it "the nation's primary source of information on criminal victimization." The survey is conducted annually and asks people from 135,000 households across the country whether they have been victims of both reported and unreported crime, ranging from sexual assault to home burglary to theft, among others.

The survey also compiles victim characteristics, such as their age, sex, race and income. Any person age 12 or older can be surveyed. Since July 2016, anyone age 16 or older has been asked about their sexual orientation and gender identity. The Justice Department wants to raise the minimum age for that question to 18.

Why does the Justice Department think 16- and 17-year-olds shouldn’t be asked about their sexual orientation?

The department cites "concerns about the potential sensitivity of these questions for adolescents." It has not elaborated on what exactly that means. And the responses to the questions are voluntary, not required.

The request is the latest action by the Trump administration to upset the LGBT community.

In July, the president vowed to bar transgender people from serving in the military. In September, his administration defended a Colorado baker who had refused to make a cake for a same-sex couple. In October, the Justice Department — reversing the Obama administration's policy — said federal civil rights law does not protect transgender people​ from workplace discrimination.

How much violence does the LGBT community experience?

Historically there aren't a lot of data, hence the need to collect it, LGBT advocates say. But here's what we know.

Both bisexual men and women experience higher rates of rape, violence, and stalking than straight people, according to the Centers for Disease Control and Prevention. In fact, many bisexual victims reported being raped for the first time between the ages of 11 and 24, the CDC said.

Transgender people also face a high risk of assault. Nearly half — or more than 13,000 of 27,715 — of those surveyed by the National Center for Transgender Equality in 2015 said they had been sexually assaulted at some point in their lives.

The New York Times, analyzing FBI data, also found in 2016 that LGBT people are more likely to be targets of hate crimes than any other minority group.

What data are available about crimes against LGBT people locally?

Philadelphia police track hate crimes but don't break down which group was targeted. The city's Commission on Human Relations has confirmed nine cases of hate or bias against LGBT people since November 2016.

In New Jersey, law enforcement reported 48 bias incidents against LGBT people in 2016, accounting for about 12 percent of the total 417 bias incidents. That data covers bias incidents that specifically target LGBT people; it doesn't include all crimes in which an LGBT person is a victim.

In Pennsylvania, on a statewide level, the data doesn't exist. Like many other states, Pennsylvania does not have a law banning discrimination based on sexual orientation. That makes it difficult to track hate crimes against LGBT people.

The National Crime Victimization Survey does not break down data by location.

Do other federal surveys ask teenagers about their sexual orientation?

Yes. The CDC's Youth Risk Behavior Survey asks high school students, "Which of the following best describes you?" Students can select: Heterosexual, gay or lesbian, bisexual, or not sure.

What happens now with the Justice Department’s proposal?

The public has until May 11 to make comments about the proposal. The Office of Management and Budget is reviewing it. If the office approves the changes, they would go into effect six months later.