the 2001 census 71.6% of all respondents indicated that they were Christians, with the next largest faiths (by number of adherents) being Islam (2.8%), Hinduism (1.0%), Sikhism (0.6%), Judaism (0.5%), Buddhism (0.3%) and all other religions (0.3%). [ 325 ] 15% of respondents stated that they had no religion , with a further 7% not stating a religious preference. [ 326 ] A Tearfund survey in 2007 showed only one in ten Britons actually attend church weekly. [ 327 ] Between the 2001 and 2011 census there was a decrease in the amount of people who identified as Christian by 12%, whilst the percentage of those reporting no religious affiliation doubled. This contrasted with growth in the other main religious group categories, with the number of Muslims increasing by the most substantial margin to a total of about 5%. [ 328 ] Migration Estimated foreign-born population by country of birth, April 2007 – March 2008 The United Kingdom has experienced successive waves of migration. The Great Famine in Ireland resulted in perhaps a million people migrating to the UK. [ 335 ] Over 120,000 Polish veterans settled in Britain after World War II, unable to return home. [ 336 ] After World War II, there was significant immigration from the colonies and newly independent former colonies, partly as a legacy of empire and partly driven by labour shortages. Many of these migrants came from the Caribbean and the Indian subcontinent . [ 337 ] The British Asian population has increased