Top 20 most livable countries

The United Nations is out with its annual list ranking the quality of life in countries around the world. For the 2015 Human Development Index, 188 nations were evaluated on criteria including life expectancy, years of education, and per capita income. Forty-nine of them achieved a ranking in the top category, which the U.N. dubs "Very High Human Development."

Here's a look at the 20 countries that rated the best, starting with Japan, in 20th place.

19. Luxembourg

Luxembourg came in at #19 on the list. Worldwide, the U.N. says quality of life as measured by the Human Development Index continues to improve, but at a slower pace than in past years.

18. Israel

Israel ranked high on the list at #18. Its war-torn neighbor Syria experienced a steep decline, dropping 15 places this year.

17. South Korea

South Korea moved up two spots since last year's report. Its communist neighbor, North Korea, was one of just seven countries in the world the U.N. was unable to rank.

16. Iceland

Iceland dropped slightly, from #13 to #16 this year.

15. Britain (tie)

Britain consistently ranks high on the list.

14. Sweden (tie)

Sweden and Britain tied this year, with equally high rankings on the Human Development Index.

13. Liechtenstein

This small principality between Austria and Switzerland has high life expectancy, education and income.

12. Hong Kong, China (SAR)

Hong Kong ranks near the top of the list, while mainland China comes in at 90th place.

11. Singapore

Singapore slipped out of the top 10 this year but still ranks very high.

10. New Zealand (tie)

The U.N. report says New Zealand achieved a top-ten ranking even though its per capita income is not as high as many other nations; it came in 32nd for gross national income per capita.

9. Canada (tie)

Canada is tied with New Zealand on this year's list.

8. United States

The United States ranked high, at #8, but that's down a few spots from last year, when it came in 5th.

7. Ireland (tie)

Ireland moved up a few notches from #11 last year.

6. Germany (tie)

Germany tied with Ireland, just missing the top 5.

5. The Netherlands

The U.N. says the top 5 countries are unchanged from last year.

4. Denmark

Denmark is #4 on the Human Development Index.

3. Switzerland

Switzerland is in third place on the U.N. list. It also recently ranked #1 on a list of the best countries for people over the age of 60.

2. Australia

Australia is #2, boosted by high life expectancy and education levels.

1. Norway

Norway topped the list for the 12th year in a row.

Since 1990, the U.N. says the number of people living in countries with very high ratings on the Human Development Index more than doubled, from about half a billion to 1.2 billion people.