Public mass shootings are occurring more frequently in recent years, and they are claiming more lives, according to an analysis of The Post’s public mass shootings database.

Four or more people have been killed in a mass shooting every 47 days, on average, since June 17, 2015. That was the evening a young white supremacist killed nine people at a Bible study in a historic African American church in Charleston, S.C.

Mass shootings, 1966-present 1970 1990 2000 June 17, 2015 2010 Mass shootings, 1966-present 1970 1980 1990 2000 2010 June 17, 2015 Mass shootings, 1966-present 1970 1980 1990 2000 2010 June 17, 2015 Mass shootings, 1966-present 1970 1980 1990 2000 2010 June 17, 2015

This weekend, the 30th and 31st such shootings since then took place just 13 hours apart.

On the morning of Aug. 3, 22 people were shot to death and 24 more wounded at an El Paso Walmart. Investigators believe the 21-year-old suspect drove almost 10 hours from his home near Dallas to target Latinos in the border city. At least eight of the dead were Mexican citizens.

After midnight, another nine people were killed and 27 injured in a bustling entertainment district in Dayton, Ohio, where a 24-year-old wearing a mask and body armor opened fire on a busy street. His younger sister was among the dead.

The pace of mass shootings has quickened

Before Charleston, eight months had passed since a 15-year-old football player killed four friends and himself at his Marysville, Wash., high school, a relatively long lull. The average time between each of the 165 shootings in The Post’s database is four months.

Before the 1999 shooting in which two teens killed 13 and wounded 24 at Columbine High School in Littleton, Colo., mass shootings took place roughly every six months. Between Columbine and Charleston, the pace was roughly one every 2½ months. After Charleston? One almost every six weeks.

Between August 1966 and April 1999, there was, on average, a mass shooting event every 180 days 17 killed, including an unborn baby, at University of Texas Tower 1970 1980 1985 23 killed at Luby’s Restaurant, Texas 1990 1999 1985 Between April 1999 and June 2015, there was, on average, a mass shooting event every 84 days 32 killed at Virginia Tech 26 killed at Sandy Hook Elementary 13 killed at Columbine High school 2000 2010 2015 From June 2015 until now, there has been, on average, a mass shooting event every 47 days 58 killed at Route 91 Harvest Festival, Las Vegas 49 killed at Pulse, a nightclub in Orlando 22 killed at shopping center in El Paso 9 killed at Emanuel African Episcopal Methodist Church 9 killed in Oregon District, Dayton, Ohio 2015 present Between August 1966 and April 1999, there was, on average, a mass shooting event every 180 days 17 killed, including an unborn baby, at University of Texas Tower 1970 1980 1985 23 killed at Luby’s Restaurant, Texas 1990 1999 1985 Between April 1999 and June 2015, there was, on average, a mass shooting event every 84 days 26 killed at Sandy Hook Elementary 32 killed at Virginia Tech 13 killed at Columbine High school 2000 2010 2015 From June 2015 until now, there has been, on average, a mass shooting event every 47 days 58 killed at Route 91 Harvest Festival, Las Vegas 49 killed at Pulse, a nightclub in Orlando 22 killed at shopping center in El Paso 9 killed at Emanuel African Episcopal Methodist Church 9 killed in Oregon District, Dayton, Ohio 2015 present Between August 1966 and April 1999, there was, on average, a mass shooting event every 180 days 23 killed at Luby’s Restaurant, Texas 17 killed, including an unborn baby, at University of Texas Tower 1970 1980 1990 1999 Between April 1999 and June 2015, there was, on average, a mass shooting event every 84 days From June 2015 until now, there has been, on average, a mass shooting event every 47 days 58 killed at Route 91 Harvest Festival, Las Vegas 49 killed at Pulse, a nightclub in Orlando 32 killed at Virginia Tech 26 killed at Sandy Hook Elementary 22 killed at shopping center in El Paso 13 killed at Columbine High school 9 killed at Emanuel African Episcopal Methodist Church 9 killed in Oregon District, Dayton, Ohio 2000 2010 2015 2015 present Between August 1966 and April 1999, there was, on average, a mass shooting event every 180 days 23 killed at Luby’s Restaurant, Texas 17 killed, including an unborn baby, at University of Texas Tower 1970 1980 1990 1999 Between April 1999 and June 2015, there was, on average, a mass shooting event every 84 days From June 2015 until now, there has been, on average, a mass shooting event every 47 days 58 killed at Route 91 Harvest Festival, Las Vegas 49 killed at Pulse, a nightclub in Orlando 32 killed at Virginia Tech 26 killed at Sandy Hook Elementary 22 killed at shopping center in El Paso 13 killed at Columbine High school 9 killed at Emanuel African Episcopal Methodist Church 9 killed in Oregon District, Dayton, Ohio 2000 2010 2015 2015 present Between August 1966 and April 1999, there was, on average, a mass shooting event every 180 days 23 killed at Luby’s Restaurant, Texas 17 killed, including an unborn baby, at University of Texas Tower 1970 1980 1990 1999 Between April 1999 and June 2015, there was, on average, a mass shooting event every 84 days From June 2015 until now, there has been, on average, a mass shooting event every 47 days 58 killed at Route 91 Harvest Festival, Las Vegas 49 killed at Pulse, a nightclub in Orlando 26 killed at Sandy Hook Elementary 32 killed at Virginia Tech 13 killed at Columbine High school 22 killed at shopping center in El Paso 9 killed at Emanuel African Episcopal Methodist Church 9 killed in Oregon District, Dayton, Ohio 2000 2010 2015 2015 present

A mass shooting has no standard definition, and The Post’s database defines it narrowly. It contains shootings since 1966 in which at least four people were killed, not including the shooters, in public places or large private gatherings. It excludes shootings tied to other crimes such as robberies and domestic killings in homes. Other definitions yield much higher numbers. As of Aug. 5, GunViolenceArchive.org, which uses a much broader definition of a mass shooting, counted 255 just this year.

Death tolls have gone up

Although the data goes back to 1966, nearly a third of the 1,196 total victims have died since Charleston, and the two deadliest shootings in U.S. history fall into that time frame.

In October 2017, a 64-year-old gambler with a cache of high-powered rifles fired from his Las Vegas hotel room window and shot 480 people in a country music festival below. Fifty-eight of them died.

Less than 15 months earlier, a security company employee killed 49 and wounded 53 in a gay nightclub in Orlando, the second-highest toll.

The shooters have gotten younger

The 169 shooters ranged in age from 11 to 73, but they were mostly young to middle-aged men, and they have trended still younger recently. Shooters before Charleston averaged just under 34 years old; from Charleston to the present, they have averaged 32 years old.

Age of mass shooters 10 The El Paso shooteR was 21 and the Dayton shooter was 24. 20 More than half of shooters since Charleston were under 30. 30 40 Four of the shooters since Charleston were 45. 50 60 The Las Vegas shooter was 64. 70 Age of mass shooters 10 20 30 40 50 60 70 The El Paso shooter was 21 and the Dayton shooter was 24. More than half of shooters since Charleston were under 30. The Las Vegas shooter, was 64. Age of mass shooters 10 20 30 40 50 60 70 The El Paso shooter was 21 and the Dayton shooter was 24. More than half of shooters since Charleston were under 30 The Las Vegas shooter was 64. Age of mass shooters 10 20 30 40 50 60 70 The El Paso shooter was 21 and the Dayton shooter was 24. More than half of shooters since Charleston were under 30 The Las Vegas shooter was 64.

Since Charleston, twenty of the 34 shooters have been in their 20s, and two were teenagers.

The venues have changed

It is hard to name a type of place where a mass shooting hasn’t occurred. Playground? Yes. Nursing home? Yes. Theater. Campground. House party. Yacht. And of course many schools, churches and military sites.

The El Paso and Dayton shootings took place in busy retail areas, two of a growing percentage that have happened in such places. More than a third of the recent shootings have occurred in or near stores, restaurants or other establishments. Before Charleston, shooters more often targeted office buildings or other types of workplace sites such as warehouses.

Stores and restaurants have been targeted 4 out of 10 times since the Charleston shooting Stores and restaurants 50% 37.5% 24% 0% Before Charleston Since Charleston Schools 50% 12.7% 12.5% 0% Before Charleston Since Charleston Offices 50% 26.3% 18.7% 0% Before Charleston Since Charleston Religious institutions 50% 9.3% 6% 0% Before Charleston Since Charleston Stores and restaurants have been targeted 4 out of 10 times since Charleston Stores and restaurants Offices 50% 37.5% 26.3% 24% 18.7% 0% Before Charleston Since Charleston Schools Religious institutions 50% 12.7% 12.5% 9.3% 6% 0% Before Charleston Since Charleston Stores and restaurants have been targeted 4 out of 10 times since the Charleston shooting Stores and restaurants Offices Schools Religious institutions 50% 37.5% 26.3% 24% 18.7% 12.5% 12.7% 9.3% 6% 0% Before Charleston Since Charleston Stores and restaurants have been targeted 4 out of 10 times since Charleston Stores and restaurants Offices Schools Religious institutions 50% 37.5% 26.3% 24% 18.7% 12.7% 12.5% 9.3% 6% 0% Before Charleston Since Charleston

While there may be trends in the types of places targeted, the geography remains unpredictable. Mass shootings have occurred all over the country, in red and blue and purple states, in huge metropolises, medium-sized cities and tiny rural towns.

They are always shocking but may be getting less surprising.

In the aftermath of nearly every mass shootings, a horrified survivor says some version of “I didn’t think it could happen here.” But in May 2018, after a gunman killed 10 at her Santa Fe, Tex., high school, 17-year-old Paige Curry had a different take.

“Eventually,” she said, “it was going to happen here.”

Some data in The Post’s mass shooting database comes from Grant Duwe, author of “Mass Murder in the United States: A History,” and Mother Jones in addition to Washington Post research.