There are currently as many as 24 Palma residents aged over 100, with the oldest being 103, but the latest survey has revealed that Palma's population is one of the youngest in Spain. The average age of Palma residents is 38.07 years, according to the census carried out by Palma city council on January 1 this year. But while this is slightly lower than the national average of 39.19, the average for Palma residents is slightly higher than in 1986. Simultaneously while the population has grown slightly older, one of the reasons being the sharp increase of the number of foreign residents, the long term birth rate has dropped. In 1986, the average age of Palma's population was 34.33, dropping to 27.39 years in 1997. At one end of the census, Palma has two residents aged 102, eight aged 101 and 12 aged 100, while in contrast, there are 2'318 members of the capital's population aged under one. The largest group, 7'081, are aged 28 and one in every four residents is aged between 23 and 36. The number of retired people is also gradually dropping. At the moment, 14 per cent of Palma's population is aged over 64. But the main reason for the reduction in the size of the retired section of the population is the growth in the number of young people, fuelled by the brief baby boom last year and an increase in the number of immigrants, many of whom are young. The Balearic population as a whole is also one of the youngest in the country, with an average age of 38. Only Andalucia, the Canaries and Murcia have a slightly young population. The immigrant boom is also tipping the balance with regards to the origins and nationalities of Palma residents. Five years ago, 95 per cent of people registered in Palma were Spanish nationals, by last year the figure had dropped to 60 per cent. Palma city council sources have said that the immigration boom which exploded last year, is continuing this year at a very similar pace.