Government figures show that around one in six children in England did not secure a place at their top choice of secondary school this year. Overall, 84% of 11-year-olds were given a spot at their first preference, whereas 16% were not.

The data shows a growth of 2.8% in the number of applications received this year, which climbed to 548,006 from 533,310 in 2015. Government officials said the increase was attributable to a “rise in births which began in the previous decade.” Statistics also show that children in areas with the highest birthrates in London, namely inner London, had only a 65.6% chance of securing a spot at their first choice.

According to Javier Espinoza of The Telegraph, 96% of children were offered a place at one of their preferred schools; families usually design a list of five or six schools in order of preference. But these new statistics showed that a child’s of chances of obtaining a place at their top choice schools depended very much on where they live.

Primary schools in areas of high population growth have been forced to expand quickly, constructing new classrooms and converting existing buildings into academic centers to accommodate growing numbers of students. Council leaders, according to The Guardian, have warned authorities that they would struggle in creating new secondary schools because of government pressure for new schools to be academies.

“Yet this government’s fixation with free schools, which can be opened where there is no shortage of school places, has made it harder and harder to ensure there are enough good school places in every local area,” said Labour’s shadow secretary of state for education, Lucy Powell. “It is time for ministers to give local areas adequate powers to plan for new places and remove the bureaucracy that councils face when it comes to opening and expanding schools.”

Many in England have expressed concern about the effect that migration is having on the nation’s school system. Though fewer than 5% of the spots needed were for children of EU migrants, the majority of these migrants are concentrated in urban areas, which disproportionately affected Londoners. The greater pressure on schools, however, is from a rising UK birth rate.

The spike in the birthrate has already put pressure on primary schools, but it is just beginning to have an impact on the enrollment in secondary schools. For example, In 2013, 66,495 pupils did not secure a place at their preferred school, and that figure increased to 77,148 in 2014. In 2015, the figure continued to rise to 84,263, and it surged again this year.

The South West region had the highest proportion of first choice offers at 91.9%, followed by the North East at 91.8%.

Unsurprisingly, London had the lowest proportion of applications receiving an offer from their first choice. The Daily Mail reports that 17,500 students in London will be forced to travel outside of their home borough to attend school. Previously, students have reported problems with having to commute long distances to schools in other parts of the city.

Despite the troubling news, a Department for Education spokesman remained optimistic about these new statistics, arguing that the government is successfully managing the country’s population growth:

“Delivering good quality school places is a top priority for this government and today’s figures show that the system continues to work. The vast majority of pupils were offered a place at their first choice school, and more than 95% received offers from one of their top three choices … We will continue to invest and work hard to ensure every child has an excellent education that allows them to reach their full potential.”