In 2015 alone, over 1.1 billion trips were made on bullet trains in China, more than 45 percent of the country's total railway passenger delivery.[Photo/Xinhua]

There have been more than 5 billion passenger trips on China's world-renowned bullet trains in eight years, according to new data from the national rail operator.

Since its debut in 2008, China's high-speed railway (HSR) has seen an average annual growth of over 30 percent in passenger trips, the China Railway Corporation (CRC) said on Thursday, the day after China announced plans to double its length of HSR by 2025.

In 2015 alone, over 1.1 billion trips were made on bullet trains in China, more than 45 percent of the country's total railway passenger delivery.

For a nation as large and populous as China, the HSR is charged with overcoming the "bottleneck" in the development of the railway, which is vital for mass transportation, said transportation expert Gu Zhongyuan.

Some 4,200 bullet trains operate on the HSR every day, facilitating over 4 million passenger trips, according to an employee with the official train ticketing website 12306.com.

One of the countless people to benefit is Wang Liya, a mother of two who lives in Guiyang, Southwest China's Guizhou province, which used to be a 21-hour train trip away from her husband and the children's father's workplace of Guangzhou in south China's Guangdong Province.

"It's now much more convenient to visit their dad," said Wang of a high-speed train service launched in late 2014 that cut the journey down to only four hours, enabling far more frequent family reunions.

There are many other reasons behind the stellar growth in passenger trips besides the speed, including accessibility, safety and punctuality, all of which has enabled the CRC to find more and more customers worldwide.