The economic participation and opportunity gap between the sexes stands at 60 percent worldwide, an improvement of only 4 percentage points since WEF measurements began in 2006.
The economic sub-index reflects three measurements: the difference between genders in labor force participation rates; wage equality; and the female-to-male ratio across a range of professions.
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The organization estimates it will take 81 years for the world to close this gap completely.
Two sub-Saharan African nations took top spots on the economic sub index: Burundi and Malawi ranked first and third respectively. Burundi is one of the few countries in the world to adopt a gender quota for its legislature - an attempt to promote the participation of women in politics.
"Much of the progress on gender equality over the last ten years has come from more women entering politics and the workforce. In the case of politics, globally, there are now 26 percent more female parliamentarians and 50 percent more female ministers than nine years ago," said Saadia Zahidi, head of the gender parity program at the World Economic Forum and lead author of the report.
Nordic nations remained the world's most gender-equal societies.
Iceland has led for the last six years due to steady increases in female-to-male ratios among legislators, senior officials and managers. Women in Iceland also have a high ability to rise to positions of enterprise leadership, the report showed, emphasizing its in maximizing its return from investment in female education.
Rwanda debuted on the index, taking seventh spot. More than 60 percent of parliamentarians in the poverty-stricken country are women, among the highest proportions globally.
Meanwhile, the world's biggest economy, the U.S., ranked 20th with almost 75 percent of its overall gender gap closed. However, the country performed poorly on the health and survival sub-index, ranking 62nd; it was eclipsed by poorer nations like Bolivia and Bulgaria.
The Philippines was the only Asia-Pacific nation on the top ten list; it ranked 9th, down four spots from last year. New Zealand and Australia ranked 13th and 24th, respectively.
As of 2014, the region closed 66 percent of its overall gender gap, due to low scores in areas like sex ratio at birth and health life expectancy.
Of the 111 countries covered in the WEF report over the last nine years, six have seen prospects for women deteriorate: Sri Lanka, Mali, Croatia, Macedonia, Jordan and Tunisia.
"Achieving gender equality is obviously necessary for economic reasons. Only those economies who have full access to all their talent will remain competitive and will prosper," said Klaus Schwab, the World Economic Forum's founder and executive chairman.