Despite growing awareness of hate crimes, the share of those crimes reported to police has fallen in recent years.

Nearly 2 of 3 hate crimes go unreported to police, the Justice Department's Bureau of Justice Statistics said. For the years 2003-06, 46 percent of hate crimes were reported to police. But more recently, in 2007-11, just 35 percent were reported.

There was an increase in the percentage of victims of violent hate crimes who didn't report the crime because they believed the police could not or would not help, from 14 percent in 2003-06 to 24 percent in 2007-11, the BJS said.

Violence accounted for 84 percent of the hate crimes during 2003-06 but rose to 92 percent during 2007-11.

The study found during 2007-11 an estimated annual average of 259,700 hate crimes against people age 12 or older.

The percentage of hate crimes motivated by religious bias more than doubled between 2003-06 and 2007-11 — from 10 percent to 21 percent. Meanwhile, the percentage motivated by racial bias dropped from 63 percent to 54 percent.

In the years 2007-11, whites, blacks and Hispanics had similar rates of violent hate crime victimization.

The data in the latest report comes primarily from the National Crime Victimization Survey, which has been collecting information on crimes motivated by hate since 2003.