The UK's economy has not changed as much as the population structure nor the ethnic composition since 2001.
Between 2001 and 2015 there has been a decline in primary and manufacturing industries and an increase in services.
This is also known as deindustrialisation, and has been happening since the 1980s. One reason is the increase in food imports, mechanisation of farming in the UK and the consequent decline in agricultural activity. In addition, raw materials such as coal are in abundance and more affordable overseas and so are imported, reducing these primary industries in the UK. The increase in competition from emerging countries (particularly China) and cheaper transportation costs has caused manufacturing, such as textiles to be out-sourced. This has caused secondary industries in the UK to close.
There has been a rise in the importance of the service industries - particularly the quaternary sector, also known as knowledge-based industries (KBI). This is as a result of the growth of financial services based in London as well as the development of new KBI jobs such as web design.