South Korea's Jeju-Seoul route was the busiest domestic air route with 10.2 million passengers last year, followed by the Hanoi-HCMC route with 5.9 million, according to an International Air Transport Association (IATA) report released Tuesday.

The two-hour Hanoi-HCMC route saw the biggest year-on-year jump of 54 percent in passengers from 2019, the report said.

Three of the five most traveled domestic air routes for 2020 were in China, which became the world’s largest domestic market for the first time on record last year.

The Shanghai-Shenzhen route was third busiest in the world with 3.7 million passengers, followed by Beijing-Shanghai and Guangzhou-Shanghai.

The IATA report said last year was the worst ever in the history of the aviation industry as the pandemic ravaged global travel.

A total of 1.8 billion passengers flew last year, a 60.2 percent fall over 2019.

The report estimated the industry’s net losses at $126.4 billion in total.

Vietnam suspended all international routes in March 2020 as it sought to contain the Covid-19 outbreak.

While 2020 was a challenging year for the Vietnamese aviation industry, aggressive contact tracing and quarantine measures had helped Vietnam contain the virus for much of the year.