Every U.S. presidential election is a grueling marathon of cross-country travel on private jets, chartered commercial flights, and fancy luxury tour buses.

So it’s nothing new for candidates to spend upwards of $10 million throughout a campaign on a variety of private jet services. But it is new for a candidate to spend millions on a private jet service he owns.

With one month left before election day, Republican candidate Donald Trump has now spent more than $5.9 million on flights hosted on his own private jet service TAG Air, according to the latest operating expenditure reports from the Federal Election Commission (FEC) filed on September 22. (Some FEC data shows the amount as $6.1 million).

Using Bailiwick, an artificial intelligence tool for finding more detailed information in campaign finance data, Skift was able to identify travel spending patterns by the candidates, and then confirm more details with FEC filings.

Democrat Hillary Clinton, however, has spent more of her campaign cash on private flights than Trump. She’s spent $11.9 million on flights from Executive Fliteways, a private jet service based in Ronkonkoma, N.Y.

Clinton’s campaign, to this point, has been more widely funded by voters and voter groups than Trump’s; he’s receivedĀ $169,731,955 in funding overall from supporters, compared to Clinton’sĀ $386,372,776.

When it comes to jet travel, Trump has diversified his spending among four different private jet charter services. His campaign has also relied on Hotels.com as its online booking site of choice, while Clinton’s camp has used Expedia most often.

Among commercial airlines, American Airlines and Delta Air Lines are the most commonly used by both Clinton and Trump staff.

Looking at which airline executives have contributed the most to the campaigns, former Delta Air Lines CEO Richard Anderson has quietly become a major Democratic party donor. Trump has received little industry support, except from a small number of members of the extended Marriott family (but not nearly as much as Republican candidate Mitt Romney received from the family’s leaders in 2012).

Neither campaign has used sharing economy services regularly. Clinton has spent $17,567 on Uber rides, while Trump has spent $9,204. Both have made two Airbnb bookings in the last two years, as well.

These numbers, of course, do not include travel bookings made by campaign employees who are later reimbursed by the campaign; Trump’s campaign seems to allow more employees to self-book and later expense their trip.

Here are the top ten travel companies with which the presidential campaigns are spending money.

Top 10 Travel Companies for Presidential Campaign Spending

ClintonTrump
CompanySpendingCompanySpending
Executive Fliteways$10,386,316TAG Air (Trump owned)$5,928,244
American Airlines$688,573Private Jet Services$4,272,872
Delta Air Lines$668,024Air Charter Team$1,355,756
Avis Rent-a-Car$441,140.60Hotels.com$1,092,315
United Airlines$354,185Advanced Aviation Team$524,805
Expedia$336,029.15Delta Air Lines$451,317
Southwest Airlines$225,567.40American Airlines$314,361
Enterprise$170,796.70Enterprise$268,399
Hertz$150,574.07Trump Hotels$203,324
Wyndham$150,221.97Hilton$140,822
Photo Credit: Republican presidential nominee Donald Trump and Democratic presidential nominee Hillary Clinton shake hands during the presidential debate at Hofstra University in Hempstead, N.Y.Donald Trump has often used election funds to pay his own company for private jet charters. David Goldman / Associated Press