GENEVA (AP) — The global gap in earnings between men and women will not be closed for another 170 years if current trends continue, according to a new report from the World Economic Forum.

The Switzerland-based forum's annual Global Gender Gap Report , released Tuesday, lists economics and health as the most challenging disparities between men and women worldwide.

Of the economic divide, the report says that "at the current rate of change, and given the widening economic gender gap since last year, it will not be closed for another 170 years."

The report has more positive findings when it comes to the gender gap on educational attainment, which it says "could be reduced to parity within the next 10 years."

The widest gap between the sexes, according to the survey, is in political empowerment. But the forum notes that significant progress has been made in narrowing that divide since its first gender gap report was released in 2006.

Four Nordic countries, Iceland, Finland, Norway and Sweden, top the Global Gender Gap index, which measures differences in economics, education, health and political empowerment among 144 countries. No country has fully closed its overall gender gap, but those in the top five, which also includes Rwanda, have closed more than 80 percent of theirs.

The U.S. placed 45th in the index, down from 28th in 2015. The report cites a decline in the number of women participating in the labor force over the past year as a partial reason for the drop. However, it also notes that the U.S. has attained parity among genders in education.

Yemen comes in last in the index, with the report finding that it has closed just over 51 percent of its overall gender gap.