Prices for air tickets during the Chinese Lunar New Year holiday rose in most domestic cities while the number of tickets for infants increased sharply, according to big data jointly released by Beijing News and Chinese travel giant Ctrip.

Spring Festival falls on Jan. 27 this year, with passenger flow expected to peak from Jan. 24 to 26. Another surge is expected from Feb. 2 to 4 as holidaymakers return to their cities of work.

Prices for roundtrip tickets starting from first-tier cities such as Beijing, Shanghai and Guangzhou increased by less than 4 percent over last year, according to Ctrip. The average price of a roundtrip air ticket starting from Beijing was the most expensive, at 2,836.2 yuan ($414) among 12 big cities, the big data showed.

Upgrades were a major reason for the price rise, Ctrip said. The number of passengers buying first and business-class tickets increased 131 percent over the previous holiday season. Travelers aged over 60 increased 49.9 percent, the statistics show.

Buying a ticket from Shanghai to Hetian in Northwest China's Xinjiang Uygur autonomous region required booking 188 days in advance, making it the most difficult route to get an air ticket for.

This year's travel will also see more infant air passengers. Some 18.1 percent more infant air tickets have been booked, double the rise of children's tickets, Ctrip said. About 26.5 percent of all air travelers who bought tickets through the agency were born during the 1990s.

Many routes are entirely booked from Jan. 24 to 26, the three days before Lunar New Year's eve. Flights from Beijing to Fuzhou, Yantai or Wenzhou have only first or business-class tickets available during the three-day period. But travelers can get a steep discount on tickets from Chongqing to Beijing over those three days, which cost just 120 yuan on average.