The 737 is used by more than 500 airlines. 737s fly to 1,200 places in 190 countries. Over 10,000 737s have been ordered by airlines. 7,283 have been delivered. Over 4,500 are still being used by airlines. On average, there are always 1,250 737s flying. On average, a 737 takes off or lands every five seconds. 25% of the world's jet airliners are Boeing 737s.