Birth dearth: 20 countries with lowest birth rates

Food shortages. Pollution. Outbreaks of disease. Experts say those are among the problems that will become more entrenched as the world's population continues to grow. In 2011, the global population will surpass 7 billion, up from 6 billion people as recently as 1999, according to Harvard researchers.

New data from the CIA show that birth rates vary tremendously around the world. Where does the U.S. rank? And what about other countries? Keep clicking to see 20 nations with the world's lowest birth rates...

20. Switzerland

Switzerland kicks off the list of 20 nations with the lowest rates of birth, with 9.53 births for every 1,000 people.

19. Bulgaria

Births per 1,000 people: 9.32

18. Lithuania

Births per 1,000 people: 9.29

17. Greece

Births per 1,000 people: 9.21

16. Serbia

Births per 1,000 people: 9.19

15. Italy

Births per 1,000 people: 9.18

14. Macau

Births per 1,000 people: 9.03

13. San Marino

Births per 1,000 people: 9.02

12. Taiwan

Births per 1,000 people: 8.90

11. Bosnia and Herzegovina

Births per 1,000 people: 8.89

10. Slovenia

Births per 1,000 people: 8.85

9. Czech Republic

Births per 1,000 people: 8.70

8. Austria

Births per 1,000 people: 8.67

7. South Korea

Births per 1,000 people: 8.55

6. Singapore

Births per 1,000 people: 8.50

5. Saint Pierre and Miquelon

Births per 1,000 people: 8.32

4. Germany

Births per 1,000 people: 8.30

3. Hong Kong

Births per 1,000 people: 7.49

2. Japan

Births per 1,000 people: 7.31

1. Monaco

The most densely populated country in the world also happens to have the lowest birth rate - who knew? Monaco's birth rate is 6.94 per 1,000 people.

73. United States

Out of the 221 countries on the list, the U.S. has the 73rd lowest birth rate, with 13.83 births per 1,000 people.