The Boeing 737-800 NG is widely used around the world.

The Boeing 737-800 NG, the model that crashed in China on Monday, is a workhorse of the skies.

There are nearly 25,000 passenger planes in service worldwide, according to Cirium, an aviation data provider. Of those, about 4,200, or 17 percent, are Boeing 737-800 NGs. China is home to nearly 1,200 of those planes, followed by Europe, with nearly 1,000, and the United States, with nearly 800.

American Airlines has 265 737-800 NGs in service, while Southwest Airlines has 205, United Airlines has 136 and Delta Air Lines has 77, according to Cirium. Boeing delivered nearly 5,000 of the planes to customers between 1998 and 2020, according to Boeing data.

China is the largest market for Boeing planes after the United States. Last year, Boeing forecast that the number of commercial planes in China would double by 2040, with Chinese airlines needing 8,700 new aircraft by then, valued at about $1.47 trillion.

The country is perhaps more crucial for Boeing’s leading rival, Airbus. Last year, Airbus delivered 142 commercial aircraft to China, its largest single-country market, representing a quarter of Airbus’s global commercial aircraft production.

Airbus has a mammoth assembly line in the city of Tianjin, producing the A320 single-aisle planes and A330 wide-body passenger jets. It also has relationships with Chinese airline and helicopter operators, and many components in Airbus jets are made by Chinese companies. The value of the Airbus and Chinese cooperation reached around $500 million in 2015.

Liz Alderman contributed reporting.