married population accounts for 49.7% of Sydney whilst 34.7% of people have never been married. 48.9% of families are couples with children, 33.5% are couples without children, and 15.7% are single-parent families. Ancestry and immigration Most immigrants to Sydney between 1840 and 1930 were British, Irish or Chinese. At the 2021 census, the most commonly nominated ancestries were: At the 2021 census, 40.5% of Sydney's population was born overseas. Foreign countries of birth with the greatest representation are Mainland China, India, England, Vietnam, Philippines and New Zealand. At the 2021 census, 1.7% of Sydney's population identified as being Indigenous — Aboriginal Australians and Torres Strait Islanders. Language A language other than English is used in 42% of households in Sydney. The most widely used non-English languages at home are Mandarin (5%), Arabic (4.2%), Cantonese (2.8%), Vietnamese (2.2%) and Hindi (1.5%). Religion In 2021, 30.3% of Sydney residents identified themselves as having no religion. Christianity was the largest religious affiliation at 46%, the largest denominations of which were Catholicism at 23.1% and Anglicanism at 9.2%. The most common non-Christian religious affiliations were Islam (6.3%), Hinduism (4.8%), Buddhism (3.8%), Sikhism (0.7%), and Judaism (0.7%). About 500 people identified with traditional Aboriginal religions. The Church of England was the only recognised church before Governor Macquarie appointed official Catholic chaplains in 1820. Macquarie also ordered the construction of churches such as St Matthew's, St Luke's, St James's, and St Andrew's. Religious groups, alongside secular institutions, have played a significant role in education, health and charitable services throughout Sydney's history. Crime Crime in Sydney is low, with The Independent ranking Sydney as the fifth safest city in the world in 2019. However, drug use is a significant problem. Methamphetamine is heavily consumed compared to other countries, while heroin is less common. One of the biggest crime related issues to face the city in recent times was the introduction of lock-out laws in February 2014, in an attempt to curb alcohol fuelled violence. Patrons could not enter clubs or bars in the inner-city after 1:30am, and last drinks were called at 3am. The lock-out laws were removed in January 2020. Culture Science, art, and history Ku-ring-gai Chase National Park is rich in Indigenous Australian heritage, containing around 1,500 pieces of Aboriginal rock art – the largest cluster of Indigenous sites in Australia, surpassing Kakadu, which has around 5,000 sites but over a much greater landmass. The