Hong Kong was rated the world's freest economy for a 17th straight year in a ranking by the U.S.-based Heritage Foundation, above rivals Singapore and Australia for the title.

Hong Kong, with a score of 89.7, is well above the world average of 59.7, the Washington-based Heritage Foundation said in its 2011 Index of Economic Freedom report released on Wednesday.

The study assesses 183 economies, out of which mainland China ranks 135th.

Hong Kong, one of the world's most competitive financial and business centers, demonstrated a high degree of resilience during the global financial crisis, the report said.

Freedom in trade and finance was the biggest boost to Hong Kong's ranking, while investment freedom and property rights, business and monetary freedom all scored highly.

The United States fell to the 9th freest from 8th last year and United Kingdom slipped to 16 place from 11 in 2010 due to more policy responses to the global economic turmoil, it added.

North Korea ranked 179th, at the bottom of the list with a score of 1.0, followed by Zimbabwe in 178th place with a score of 22.1. Afghanistan, Iraq, Liechtenstein and Sudan were unranked.

Rank Economy Overall score (out of 100)

1 Hong Kong 89.7

2 Singapore 87.2

3 Australia 82.5

4 New Zealand 82.3

5 Switzerland 81.9

6 Canada 80.8

7 Ireland 78.7

8 Denmark 78.6

9 United States 77.8

10 Bahrain 77.7

(Reporting by Farah Master and Alison Leung; Editing by Jacqueline Wong)

Australia Zimbabwe China Afghanistan