1948 which de-jure allowed the migration of upwards 800,000,000 British subjects who were now British citizens in law, modern mass migration to the United Kingdom began. During this decade West Indians from the Caribbean, those from Jamaica and so on began to arrive. During the middle of the 1960s to the 70s, migration flipped in origin to the majority of those arriving being of South Asian origin from the Indian sub-continent. Immigration restrictions, in response to the ever increasing number arriving, were introduced, such as the Commonwealth Immigrants Act of 1962, Commonwealth Immigrants Act of 1968 and the Immigration Act of 1971. Through the 1970s, 80s and early 90s, net migration to the United Kingdom was often negative in terms of numbers, with more people leaving the country, than entering in total. Since 1994, net migration in numbers has been in the positives, with more people entering the country, rather than leaving. Migration increased fourfold following the election of Tony Blair in 1997, immigration restrictions were undone such as the primary purpose rule. In 2004, along with Ireland and Sweden, Britain was one of the only countries within the EU to not allow 'transitional controls' on migration flows from the newly joined A8 countries from Eastern Europe. Around 453,000 immigrants, which has been revised upwards in recent years, from these new counties were estimated in 2015 to have migrated to the UK. Country of birth Country of birth was first asked as a census question in 1841. In the 1980s to 1990s, around 12 to 13% of births were born to foreign born mothers. In 2004, this had risen to 20% of births being born to foreign born mothers. Below is the number of births in England and Wales in 2011 by mother's country of birth, as well as their total fertility rate. In 2014, 27% of births were to mothers born outside the UK, a 0.5-point increase since 2013. The 2014 fertility rate was higher for foreign-born mothers (2.09) than British-born mothers (1.76). In the 2010–14 time period, the most common countries of birth for mothers (excluding the UK) were Poland, Pakistan and India; and Poland and India for fathers. Within the UK, Newham, London had the highest rate of births to non-UK mothers (76.7%) and Torfaen, Wales the lowest (3.2%). The fertility rate among non-UK born women was 1.98 and among UK born women 1.50 in 2020. Internal