Doing Business rankings:

Five African countries among top 10

Singapore topped the list of business-friendly economies globally, while five of the top 10 most improved countries were in sub-Saharan Africa, according to the World Bank Group's Doing Business 2015 rankings.

The 12th annual report found that the 10 economies with the most business-friendly regulatory environments were Singapore, New Zealand, Hong Kong SAR, China, Denmark, the Republic of Korea, Norway, the United States, the United Kingdom, Finland and Australia.

The 10 economies that have improved the most compared to the previous year were Tajikistan, Benin, Togo, Côte d'Ivoire, Senegal, Trinidad and Tobago, the Democratic Republic of Congo, Azerbaijan, Ireland and the United Arab Emirates.

Sub-Saharan African countries had the highest number of regulatory reforms - 75 of 230 around the world - while emerging Europe and Central Asia had the highest percentage of improving countries. Progress was uneven in the Middle East and North Africa, with conflict-affected Syria near the bottom. South Asia saw the lowest number of reforms.

While 80% of countries in the study improved their business regulations last year, only about one-third moved up in the rankings. However, the gap between the best and worst-performing countries continues to narrow as countries improve their business climates, said manager of the Doing Business Project, Rita Ramalho.

"It's easier to do business this year than it was last year, two years ago or 10 years ago. We see that the economies that score the lowest are reforming more intensely, so they are converging toward the economies that do the best," she said.