A popular flight path across Canada has been named one of the most lucrative in the entire world for airlines.

Data from OAG Aviation Worldwide shows that flights between Vancouver and Toronto — as operated by Air Canada — travel on the tenth highest-grossing path in the world, making the airline more than $541 million U.S. in 2018/2019, and around $80 million more in 2017/2018.

The world’s 10 most lucrative airline routes:

1. London Heathrow – NY JFK
2. Melbourne – Sydney
3. Dubai – Heathrow
4. Singapore – Heathrow
5. San Francisco-Newark
6. LAX – NY JFK
7. Doha – Heathrow
8. Hong Kong – Heathrow
9. Singapore – Sydney
10. Vancouver – Toronto

(OAG)

— World Index (@theworldindex) December 11, 2019

Some social media users are speculating that the notoriously high ticket prices for flights on the YVR-YYZ route, as well as the fact that the airline industry is essentially an oligopoly within Canada, are contributing factors to the fattening of carriers' pockets.

was checking out flights Toronto ✈️ Vancouver & it’s more expensive than my flight going to NYC........... Canada is so expensive AND FOR WHAT

— t ✨ (@entropyoungks) October 2, 2019

"Not surprising. You can buy a one way economy ticket to the other side of the world for less than what Air Canada and WestJet charge for an economy flight from Toronto to Vancouver," one Redditor said.

"You can fly to the majority of Europe for almost half the price," another added.

There is also the fact that both Vancouver International Airport and Toronto Pearson International Airport are key stopover points for overseas travel — passengers from Toronto looking to fly westward across the globe often have a layover in Vancouver, and the vice versa for those from Vancouver looking to fly east out of North America.

It is starting to physically pain me that flying Toronto to Vancouver round trip is more expensive then flights to Asia #aircanada #westjet #flights #canada #aircanadarouge

— Ashley (@Astewie7) June 13, 2019

The highest revenue generating route overall was between London and New York City, which amasses more than a billion U.S. dollars for British Airways annually, largely thanks to a high number of first and business class fliers.

London's Heathrow Airport was in five of the ten top-earning routes in the world, while New York City's JFK International Airport and nearby Newark Liberty International Airport in New Jersey were the origin or destination point of seven of the top ten routes to or from North America in particular.

Among the most lucrative routes in the world were those between Melbourne and Sydney with Qantas, between London and Dubai with Emirates, and between London and Singapore with Singapore Airlines.