Suburbs also excluded are Jumpers Common, the built up area of Burton, as well as Bournemouth Airport, with the rest of the borough including the rural portions and hamlets in the Hurn and Burton parishes being 'washed over' by the green belt. Landscape features and greenfield facilities within include the rivers Stour, Moors, Avon and their floodplains, Christchurch Priory, Chapel Lane solar farm, Blackwater and St Catherine's hills, Hurn Forest, Stanpit Marsh, Mudeford Spit, and the Adventure Wonderland theme park. The New Forest National Park in Hampshire borders the green belt to the east of the borough in Burton parish. Christchurch has a population of 45,080 according to a 2007 census, making it the fourth most populous settlement in Dorset. It lies in the South East Dorset conurbation which is one of the South Coast's major urban areas with a total population of over 400,000. Over the three decades between 1971 and 2001, Christchurch's population increased by 32% from 33,768 to 44,865; and between 1991 and 2001 by 8.5%. This was more than three times the average for England and Wales (2.5%), and it is expected to grow by a further 16% to 52,100 by 2028. Between 1999 and 2006 there was a net gain of 4,200 people from migration alone (i.e. excluding births and deaths). On average 3,100 people enter the borough and 2,500 leave each year, giving a net average gain of 600 migrants. The population density of Christchurch is four times the UK average with 873 people per square kilometre (2,307 per sq mi). Christchurch has one of the oldest populations in the country with significant proportion of residents wealthy senior citizens. The percentage of the population aged over 65 in Christchurch is 30.4%, almost double the national average of 16.5%. Highcliffe on the borough's eastern boundary possesses the highest percentage of elderly residents in the entire United Kingdom at 69%. The Office for National Statistics predicted that by 2031, the percentage of residents over 65 will rise to 37.9. In 2005, the life expectancy of female residents was 83.4 years and male residents 79.7 years. This was an increase on ten years previous (1995) when the life expectancy was 82.6 years and 77.0 years for females and males respectively. In common with the rest of Dorset, Christchurch has low numbers of black and minority ethnic groups: the vast majority (96.83%) consider themselves to be White British.