General Motors CEO Mary Barra tops Fortune magazine's Most Powerful Women in Business list for the third year running. 

The ranking of 51 women includes 26 CEOs who control $1.1 trillion in market capitalization. Though the number of female CEOs among Fortune 500 companies hit a new record of 32 in 2017, that still only represents 6% of the total.

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It was “a year when the uncomfortable realities that professional women often live with privately burst into the public eye — whether it was at Uber, in the startup and VC community, or at Fox News,” the authors of the report wrote.

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Here are Fortune’s top 10 most powerful women in business for 2017 and their previous ranking a year ago.

1. Mary Barra, General Motors CEO (1)

2. Indra Nooyi, PepsiCo CEO (2)

3. Marillyn Hewson, Lockheed Martin CEO (3)

4. Abigail Johnson, Fidelity Investments CEO (5)

5. Sheryl Sandberg, Facebook chief operating officer (6)

6. Ginni Rometty, IBM CEO (4)

7. Meg Whitman, Hewlett Packard CEO (7)

8. Safra Catz, Oracle co-CEO (10)

9. Phebe Novakovic, General Dynamics CEO (8)

10. Ruth Porat, Alphabet and Google CFO (13)

See the entire list: Fortune’s Most Powerful Women of 2017

Barra topped the list once more as she presided over GM's biggest sales growth in years with revenue at the automaker rising 9% in 2016, Fortune says.

Seven newcomers made the list this year in addition to Reese Witherspoon, ranked No. 51. The Hollywood actress has her own production company, which hit big this year with the multiple Emmy-winning Big Little Lies and a retail start-up, Draper James, that features a Southern-oriented lifestyle brand.

None of the newcomers cracked the top 10. The highest-ranking addition was PG&E CEO Geisha Williams, clocking in at 19 on the list. Williams is the first Latina to run a Fortune 500 company. 

Other newcomers included: Boeing’s Defense, Space & Security CEO Leanne Caret (30), Staples CEO Shira Goodman (42), Reinsurance Group of America CEO Anna Manning (44), Hershey CEO Michele Buck (45), Ulta Beauty CEO Mary Dillon (48), and Mattel CEO Margo Georgiadis (49). 

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Fortune said editors used four criteria for the list: the size and importance of the woman's business in the global economy, the health and direction of the business, the arc of the woman's career (résumé and runway ahead), and social and cultural influence.

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