than the Yorkshire coast with temperatures of 27 °C or more. Extremes recorded at the University of York campus between 1998 and 2010 include a highest temperature of and a lowest temperature of on 6 December 2010. The most rainfall in one day was . Green belt York's urbanised areas are surrounded by a green belt that restricts development in the rural areas and parts of surrounding villages, to preserve the setting and historic character of the city. The green belt surrounds nearly all of the city and its outer villages, extending out into North Yorkshire. Demography The York urban area (built-up area) had a population of 153,717 at the time of the 2011 UK census, compared with 137,505 in 2001. The population of the City of York (Local Authority) was 198,051 and its ethnic composition was 94.3% White, 1.2% Mixed, 3.4% Asian and 0.6% Black. York's elderly population (those 65 and over) was %, however only 13.2% were listed as retired. Also at the time of the 2001 UK census, the City of York had a total population of 181,094 of whom 93,957 were female and 87,137 were male. Of the 76,920 households in York, 36.0% were married couples living together, 31.3% were one-person households, 8.7% were co-habiting couples and 8.0% were lone parents. The figures for lone parent households were below the national average of 9.5%, and the percentage of married couples was also close to the national average of 36.5%; the proportion of one person households was slightly higher than the national average of 30.1%. In 2001, the population density was . Of those aged 16–74 in York, 24.6% had no academic qualifications, a little lower than 28.9% in all of England. Of York's residents, 5.1% were born outside the United Kingdom, significantly lower than the national average of 9.2%. White British form 95% of the population; the largest single minority group was recorded as Asian, at 1.9% of the population. The number of theft-from-a-vehicle offences and theft of a vehicle per 1,000 of the population was 8.8 and 2.7, compared to the English national average of 6.9 and 2.7 respectively. The number of sexual offences was 0.9, in line with the national average. The national average of violence against another person was 16.2 compared to the York average of 17.5. The figures for crime statistics were all recorded during the 2006–07 financial year. The city's estimated