List of B737 Carriers Worldwide - Interesting....

first boeing 727. lufthansa 1968 (Comet Photo AG (Zürich), ETH-BIB Com F66-08148 Lufthansa Boeing 727-3C D-ABIC Zuerich-Kloten 060766, CC BY-SA 4.0)

A Boeing 737 takes off or lands somewhere in the world on average every 5 seconds!

To date, the Boeing series of airliners is the most successful airliner the world has seen.  Boeing's success revolves around, amongst other things, the ability to be able to upgrade their aircraft from a basic overall design that has changed little since the first 727 rolled out of the hanger in the 1968, earmarked for the German airline Lufthansa.

So which nations place their trust in Boeing?  This link provides a list of worldwide carriers by nation.