The vast majority of CEO positions, 95%, are held by men, according to research by executive search provider Heidrick & Struggles. It also found 67% rose to the CEO role from an internal promotion.

“While the advancement women have made toward the CEO role has gained momentum in recent years, we still are not seeing a significant increase to the number of appointments of women to the CEO role,” said Anne Lim O’Brien, vice chairman of the global CEO & Board Practice. “It’s clear there is much work to be done on a global scale.”

In Denmark and Italy, women held no CEO roles. In Germany, women held 1.2% of CEO roles. However, women held 6.9% of CEO roles in the US.

The survey also found that fewer than three in 10 CEOs held an MBA degree. The percentage was 34% in the US. Portugal had the highest percentage of CEOs with an MBA at 47%; Italy was the lowest at 13%.