Fewer than half of parents were able to enrol their children in the primary school of their choice - the lowest success rate for 13 years - in the first phase of allocations yesterday. School principals attributed the shortage to fierce competition in the discretionary phase - in which parents can nominate a school - brought on by a rebound in the birth rate and a move to smaller classes. Secondary schools, starved of students, are being pressed to cut classes to stave off a wave of closures. There were scenes of happiness and frustration at top primary schools across the city yesterday. At La Salle College in Kowloon, anxious parents arrived at the school gate early in the morning to check allocations of the 90 places available at the elite Catholic school. One man, who came with his wife and child, was lucky. His son was admitted through a system that accorded 5 marks to their Catholicism and another five for the child being the first born. 'I was very happy,' he said. 'We need to say thanks to God.' Alex Lau, a mainland immigrant, was less fortunate. His daughter failed to get a place at Maryknoll Convent School, in Kowloon. 'I have also applied for private and direct subsidy scheme schools for back-up,' he said. The primary-places allocation system has two rounds. In the first, or discretionary, round, 50 per cent of a school's places are set aside. A parent can apply for a place for their child at one government or aided school of their choice in this round, irrespective of where they live. The Education Bureau said 43,051 children applied for discretionary places this year, of whom 47.5 per cent, or 20,456, got a place, down from 49.2 per cent per cent last year, when 20,461 of the 41,554 applicants succeeded. It was the third consecutive year of success below 50 per cent, with the rate this year the lowest in 13 years. Cheung Yung-pong, chairman of the Subsidised Primary Schools Council, said the baby boom following the 2003 severe acute respiratory syndrome outbreak had intensified the race to the top schools. 'The children that joined the discretionary round this year were born in 2005, the year after 2004, when birth rate was at the nadir after Sars.' Census and Statistics Department figures show that a population rebound started in 2005, with 57,098 babies born that year. 'With parents flocking to a few elite schools, competition will only get more intense in future because of the population rise,' he said. 'Districts like Tai Po and Northern district, which lie along the rail line to the mainland, will see even lower success rates as more and more cross-border babies reach primary age.' Leung Siu-tong, chairman of the Aided Primary School Heads Association, said more 'small-class' teaching had further squeezed places. In the 2009-10 academic year when the 'small-class' policy has was introduced, 297 out of 463 government and aided primary schools responded by reducing their class sizes from 30 to 25. The figure has risen to 318 schools in the current academic year, while 15 more schools will run 'small classes' in the 2011-12 year, leading to an overall decrease of 1,000 primary places. Those who are not successful in getting their choice in the first round have to either apply for private or direct subsidy schools, or wait until June next year when central allocation results are announced.