According to the latest hate crime data released late last year by the Federal Bureau of Investigation, there were 5,850 reported incidents of hate-motivated crimes in 2015.

The data show that incidents were up slightly by 6 percent between 2014-2015, but have generally been on the decline since 2002.

What this data doesn’t show is that at least least 2,700 state and local police departments do not report hate crimes to the FBI, according to investigations by the Associated Press. According to a tally published by the non-profit investigative journalism group, ProPublica, more than 3,000 law enforcement agencies don’t report hate crimes to the FBI.

Here’s why this chart doesn’t tell the whole story. The entire state of Hawaii does not report hate crimes, and in many states, only a fraction of jurisdictions report.

A CGTN America analysis shows the extent of the non-reporting by each state in the map below.

The FBI data includes the number of police agencies that participate in U.S. government efforts to track hate crimes. It also includes the total population covered by those agencies. We then compared this specific population against the total estimated population for each state, based on U.S. Census Bureau estimates.

While in many states, 100 percent of the population is covered by agencies that track hate crimes for the FBI, in seven states, less than 50 percent of the population is covered by reporting agencies. Hover over the map to see how each state fares.

The percentage of the population covered is lowest in Mississippi, Alabama, Florida, and New Mexico. In these four U.S. states, only about a quarter of the population is covered by law enforcement jurisdictions that report hate crimes.

Our analysis shows that nationwide, about 12 percent of the estimated 2015 population is not covered.

VOLUNTARY REPORTING

Under FBI guidelines, law enforcement should report suspected hates crimes if a “reasonable and prudent” person would conclude a crime was motivated by bias.

While states are required under federal law to collect data on hate crimes, they are not required to report it to the FBI’s Uniform Crime Report, writes Ronald L. Davis, of the Dept. of Justice and Patrice O’Neill of Not In Our Town in Police Chief magazine.

“While 18,000 agencies in the United States do make some reports, many don’t. Some states, including Indiana, Mississippi, and New Mexico, do not even have a UCR program, so agencies in those states must report directly to the FBI, an extra step that many do not take,” Davis and O’Neill wrote.

What makes understanding hate crime data even harder to analyze is that hate crimes are “overwhelmingly underreported—by both victims and law enforcement officers” Davis and O’Neill write.

A study by the Department of Justice found that on average there were 260,000 “hate crime victimizations” per year between 2007-2011, based on anonymous responses from the National Crime Victimization Survey, Mother Jones reports.

The NCVS survey is considered the most accurate of its kind, write Davis and O’Neill. It is based on a representative sample of 90,000 households and is conducted twice a year, and collects responses on a variety of crimes, “including those not reported to police,” they added.

Indication of under-reporting of hate crimes is also evident in the Southern Poverty Law Center’s independent database.

They recently collected 437 reports of hateful intimidation and harassment from Nov. 9, 2016–the day after the presidential election–to Nov. 14, 2016.

Those reports were collected in six days and already comprise more than 13 percent of the total number of incidents the FBI reported in 2015.

Civil rights groups are concerned that newly-appointed Attorney General Jeff Sessions may not view hate crime reporting as a priority.

As a U.S. senator in 2009, Sessions opposed the Matthew Shepard and James Byrd, Jr., Hate Crimes Prevention Act that ultimately became law. The law extended hate crime protections to people harmed for their sexual orientation, or gender identity, or disability, Mother Jones reported.