Fortune reveals America's top 500 companies

Last Updated Jun 7, 2017 10:40 AM EDT

Fortune magazine is out with its annual list of America's top 500 companies. The list has been a measure of the country's most valuable businesses since it first came out in 1955. This year, the combined total revenue of all 500 companies reaches $12.1 trillion, 65 percent of the U.S. GDP.

First on "CBS This Morning," Fortune president and Time chief content officer Alan Murray revealed this year's top companies. Walmart came in first this year again, holding the spot for five years in a row. 

"They're now twice the size in terms of revenues of the next company on the list. They're really a behemoth," Murray said. "Now, they're not No. 1 in profits, they're not No. 1 in market value, but in terms of revenue's sheer size, they are No. 1."

Competitors like Amazon, ranked 12th by revenue, are "far more valued by the market" at No. 4 than Walmart, which is ranked 15th in the category. Amazon's profits also grew by 297.8 percent from 2015 to 2016.

Murray pointed out that Apple's revenue ranking fell from No. 2 last year to No. 3 this year, but it holds the top spot for the most profitable company at $45.7 billion.

As for female CEO trends for Fortune 500 companies, Murray said there's been an improvement from 21 female CEOs on last year's list to 32 this year.

"It's still an awfully small number," Murray said. "That means less than 10 percent of the CEOs of Fortune 500 companies are women, but it's a big increase. It's been stagnant for a number of years, so to see that go up is an encouraging sign."

Fortune also surveyed 72 CEOs and asked how the election of President Trump has impacted their businesses. Among them, 26.39 percent said his election was good for business, 12.5 percent said it was bad for business and 61.11 percent said it had no effect. 

These companies ranked in the top 15 on the Fortune 500 list:

1. Walmart Stores

Revenue (2016): $485.9 billion, +0.8 percent change from 2015

Profits (2016): $13.6 billion, -7.2 percent change from 2015

2. Berkshire Hathaway

Revenue: $223.6 billion, +6.1 percent change from 2015

Profits: $24 billion, 0 percent change from 2015 

3. Apple

Revenue: $215.6 billion, -7.7 percent change from 2015

Profits: $45.7 billion, -14.4 percent change from 2015 

4. ExxonMobil

Revenue: $205 billion, -16.7 percent change from 2015

Profits: $7.8 billion, -51.5 percent change from 2015 

5. McKesson

Revenue: $192.5 billion, +6.2 percent change from 2015

Profits: $2.3 billion, +53 percent change from 2015

6. UnitedHealth Group

Revenue: $184.8 billion, +17.7 percent change from 2015

Profits: $7 billion, +20.7 percent change from 2015 

7. CVS Health

Revenue: $177.5 billion, +15.8 percent change from 2015

Profits: $5.3 billion, +1.5 percent change from 2015 

8. General Motors

Revenue: $166.4 billion, +9.2 percent change from 2015

Profits: $9.4 billion, -2.7 percent change from 2015 

9. AT&T

Revenue: $163.8 billion, +11.6 percent change from 2015

Profits: $13 billion, -2.8 percent change from 2015 

10. Ford Motor

Revenue: $151.8 billion, +1.5 percent change from 2015

Profits: $4.6 billion, -37.7 percent change from 2015 

11. AmerisourceBergen

Revenue: $146.8 billion, +8.0 percent change from 2015

Profits: $1.4 billion

12. Amazon.com

Revenue: $136 billion, +27.1 percent change from 2015

Profits: $2.4 billion, +297.8 percent change from 2015 

13. General Electric

Revenue: $126.7 billion, -9.8 percent change from 2015

Profits: $8.8 billion

14. Verizon Communications

Revenue: $126 billion, -4.3 percent change from 2015

Profits: $13.1 billion, -26.6 percent change from 2015 

15. Cardinal Health

Revenue: $121.5 billion, +18.5 percent change from 2015

Profits: $1.4 billion, +17.4 percent change from 2015 

For the full Fortune 500 list, visit Fortune.com