Can you guess this country in five clues?

1. The life expectancy of an average citizen of the country is 78.38 years old   

1. It is about the size of Delaware

1. The most common languages spoken there are Malay, English, and Chinese

4. There major trading partners include Japan, Australia, Singapore, and India

5. They have one airport 

Cites:

https://www.factmonster.com/world/countries/brunei

http://theconversation.com

https://www.upsidedowntext.com/