U.S. Democratic presidential candidate Hillary Clinton waves as she sits down to talk during a campaign stop at a small restaurant in Vallejo, California, United States June 5, 2016.   REUTERS/Mike Blake  - RTSG4YMAmerica may be on the verge of electing a female President, but women are still struggling to compete with men for the highest positions in corporate America.  

There are 21 Female CEOs on the 2016 Fortune 500 list. That means that women hold only 4.2% of CEO positions in America’s largest companies. 

The Fortune 500 annual list ranks the largest corporations in the US by revenue. 

Of the 29 companies added to the list this year, just one, Mary Laschinger of paper products and distribution company Veritiv, is a woman.

Mary T. Barra, CEO of General Motors, is the only woman to head a company in the top 10.  

There were 24 women in last year’s list and 24 in 2014. There are a number of valid reasons that the number has fallen, including retirement, company splits and spin-offs that mean the newly created companies are too small to qualify for Fortune’s list.

We’ve picked out the top nine female CEOs, so scroll through to see who made the list, and meet America’s most powerful women bosses.  

Mary T. Barra

Mary T. Barra

Company: General Motors

Company Ranking: 8

Revenue ($ billion): $152.4

Background: Mary Barra has worked at General Motors for 36 years, starting as a co-op student in 1980. She rose through the ranks to become VP of Global Manufacturing Engineering, VP of Global Human Resources, Executive VP of Global Product Development, Global Purchasing and Supply Chain, and finally CEO, a role she assumed in January 2014. 

Barra graduated with a Bachelor of Science degree by Kettering University and earned an MBA from Stanford. 

Virginia M. Rometty

 Company: IBM

Ranking: 31

Revenue ($ billion): $82.5

Background: Virgina “Ginni” Rometty started her career at General Motors and moved over to IBM’s Detroit Office as a systems engineer. She worked in IBM’s Consulting Group before becoming Senior VP and Group Executive for Sales, Marketing and Strategy and eventually President and CEO in 2011.

She graduated from Northwestern University with a Bachelor’s degree in Computer Science and Electrical Engineering. 

Indra K. Nooyi

Company: PepsiCo

Ranking: 44

Revenue ($ billion): $63.0

Background: Indray Nooyi began her career in consulting, interning with Booz Allen Hamilton and working at BCG. She joined PepsiCo in 1994 and was appointed President and CFO seven years later, before becoming CEO of the company. Nooyi is credited with moving the company towards healthier alternatives. 

Indray Nooyi was born in Chennai, India and received a Bachelor’s degree from Madras Christian College, an MBA from the Indian Institute of Management Calcutta and a Masters from the Yale School of Management.

See the rest of the story at Business Insider