The number of planes owned and operated by airlines in the Republic of Korea surpassed 400 last year, data showed, marking the highest figure since record-keeping began, Yonhap News Agency reported.

Domestic airlines operated a total of 416 airplanes, including 42 cargo planes, as of late last year, up 23 from a year before, according to the data submitted to Rep. Lee Yeon-hee of the main opposition Democratic Party (DP).

This marks the highest number of planes since a private airplane was first registered in the country in 1977.

The number is expected to climb further this year as domestic airlines have plans to introduce 54 new planes while disposing of 38 outdated aircraft.

The number of plane registrations had been on a steady rise to surpass the 300 mark in 2015 and reach the previous record of 414 in 2019 before dropping the following year due to the COVID-19 pandemic.

By airline, local industry leader Korean Air had the largest share of 39.7 percent of the total, or 165 planes, followed by Asiana Airlines at 83 planes and Jeju Air at 41, including the plane lost in the deadly crash that claimed 179 lives on Dec. 29.

By type of aircraft, 62 percent, or 258 planes, were made by aircraft manufacturer Boeing, followed by Airbus at 38 percent, or 158 planes.