Too many, even all over the world.

Marrige is like buying a car, which needs maintaining. Using unleaded gas, regularly changing oil and parts help. However, like any tools and appliances, it will be worn out; how long a car can be used depends on (i). the original car quality, (ii). how to use it. If you want your car lasting long, buy a BMW and keep good maintainance. In addition, park your car in a safe place, avoiding somebody to touch it. This is very important; there are a lot of thieves.