When the thunder of gunfire broke through the revelry of a country music dance hall packed with young people kicking back on "college night," Thousand Oaks, California, added its name to a dark roster: The site of the 307th mass shooting in the U.S. this year.

And an even grimmer statistic was marked: The 307th mass shooting took place on the 311th day of the year – an average of a deadly incident almost every day so far this year.

The Wednesday night massacre at the Borderline Bar and Grill, which left 13 people dead, including the gunman, became the nation's latest mass shooting, according to data from the Gun Violence Archive, a not-for-profit organization that provides online public access to information about gun-related violence.

In all, 328 people died in those incidents, and 1,251 were injured, according to the data. The numbers include incidents in which four or more people were shot or killed, not including the shooters, according to the archive.

The rampage also came during three weeks of hate and terror that have jolted the country: a bloodbath at a synagogue in Pittsburgh that left 11 elderly people dead and a series of 16 pipe bombs mailed to prominent Democrats, CNN and critics of President Donald Trump.

The incident was also the deadliest mass shooting in the U.S. in 2018 since 17 classmates and teachers were gunned down at a Parkland, Florida, school on Valentine's Day.

That shooting galvanized a student-led anti-gun movement that turned young people into activists. Just 24 hours before the spree in Thousand Oaks, Parkland survivors had celebrated the toppling of some NRA-backed candidates in Tuesday's midterm elections.

Thursday morning, one of those students, Cameron Kasky, 17, lamented the pain of witnessing more bloodshed:

“The Mayor of Thousand Oaks is completely right," Kasky tweeted. "No community is truly safe from these mass shootings. We’ve seen this far too many times. How many anomalies are there going to be? How many times are we going to here (hear) “nobody would’ve thought it would happen here?”

2018 has seen several high-profile mass shootings:

Five people were gunned down in the newsroom of the Capital Gazette in Annapolis, Maryland, on June 28.

Ten were fatally shot at Santa Fe High School on May 18.

Four people killed at a Waffle House in Nashville, Tennessee, on April 22.

California's previous worst 2018 mass shooting came on Sept. 12, when a Bakersfield man fatally shot five, including his wife, before killing himself.

More:'Horrific scene': Sheriff’s sergeant, 11 others dead in Thousand Oaks, California, bar shooting

Also:Some Thousand Oaks victims survived mass shooting in Las Vegas, reports say

Related:'He died a hero': Ventura County Sheriff Sgt. Ron Helus among those killed in bar shooting

Here is a look at other shooting sprees in the U.S.:

• Oct. 1, 2017: Stephen Paddock, 64, fired more than 1,000 rounds from a 32nd-floor suite at a nearby hotel on concertgoers at the Route 81 Harvest Music Festival, killing 58 people and leaving hundreds injured. Paddock was later found dead of a self-inflicted gunshot wound. His motive remains unknown.

• June 12, 2016: Omar Mateen, a 29-year-old security guard, kills 49 people and wounds 58 others at Pulse, a gay nightclub in Orlando, Florida, that was hosting a Latin night. Mateen was killed by police. It was the deadliest terror attack in the U.S. since 9/11 and at the time was the worst mass shooting in the nation by a single gunman.

• April 16, 2007: Seung Hui Cho, a 23-year-old student, went on a shooting spree at Virginia Tech in Blacksburg, Virginia, killing 32 people, before killing himself.

• Dec. 14, 2012: Adam Lanza, 20, gunned down 20 children and six adults at Sandy Hook Elementary School before killing himself.

• Oct. 16, 1991: George Hennard, 35, crashed his pickup through the wall of Luby's Cafeteria in Killeen, Texas. He shot and killed 23 people before committing suicide.

• July 18, 1984: James Huberty, 41, gunned down 21 adults and children at a McDonald's in San Ysidro, California, before being killed by police.

• Aug. 1, 1966: Charles Joseph Whitman, a former U.S. Marine, shot and killed 16 people from a university tower at the University of Texas in Austin before being shot by police.

• Aug. 20, 1986: A part-time mail carrier, Patrick Henry Sherrill, shot and killed 14 postal workers in Edmund, Oklahoma, before killing himself.

• Dec. 2, 2015: Syed Farook and Tashfeen Malik, a married couple living in Redlands, California, opened fire at a San Bernardino County Department of Public Health training event and holiday party, killing 14 people and injuring 22 in a matter of minutes. Farook, an American-born U.S. citizen of Pakistani descent, worked at the health department. Malik had pledged allegiance to the Islamic State in a Facebook post before the shooting.

• Nov. 5, 2009: U.S. Army Maj. Nidal Hasan fatally shot 13 people and injured 30 others at Fort Hood near Killeen, Texas. Hasan, a psychiatrist, appeared to have been radicalized by an Islamic cleric. He was convicted and sentenced to death.

• Sept. 16, 2013: Gunman Aaron Alexis, 34, fatally shot 12 people and injured three others at the headquarters of the Naval Sea Systems Command in Washington, D.C. He was later killed by police.

• July 20, 2012: James Holmes gunned down 12 people in an Aurora, Colorado, movie theater. Last year he was convicted of first-degree murder and attempted murder and sentenced to 12 consecutive life sentences plus 3,318 years without parole.

• Oct. 1, 2015: Christopher Harper-Mercer, a 26-year-old student at Umpqua Community College near Roseburg, Oregon, shot an assistant professor and eight students in a classroom. After a shootout with police, he committed suicide.

• June 18, 2015: A gunman opened fire at a weekly Bible study at the Emanuel African Methodist Episcopal Church in Charleston, South Carolina. Nine people were killed, including pastor Clementa Pinckney; a 10th victim survived. The morning after the attack, police arrested a suspect, Dylann Roof, 21, who said he wanted to start a race war. In December 2016, Roof was convicted of 33 federal hate crimes charges, and in January he was sentenced to death.

• July 16, 2015: Muhammad Youssef Abdulazeez opened fire on two military installations in Chattanooga, Tennessee. The first was a drive-by shooting at a recruiting center; the second was at a U.S. Navy Reserve center. Four Marines and a Navy sailor died; a Marine recruit officer and a police offer were wounded. Abdulazeez was killed by police in a gunfight.

• Nov. 27, 2015: A gunman attacked a Planned Parenthood clinic in Colorado Springs, Colorado, killing a police officer and two civilians and injuring nine others. Robert Lewis Dear was taken into custody after a five-hour standoff and charged with first-degree murder.