jobs, being the fifth most important employment in Norfolk. The visitor economy had increased in value by more than £500 million since 2012. Important business sectors also include energy (oil, gas and renewables), advanced engineering and manufacturing, and food and farming. Much of Norfolk's fairly flat and fertile land has been drained for use as arable land. The principal arable crops are sugar beet, wheat, barley (for brewing) and oil seed rape. The county also boasts a saffron grower. Over 20% of employment in the county is in the agricultural and food industries. Well-known companies in Norfolk are Aviva (formerly Norwich Union), Colman's (part of Unilever), Lotus Cars and Bernard Matthews Farms. The Construction Industry Training Board is based on the former airfield of RAF Bircham Newton. The BBC East region is centred on Norwich, although it covers an area as far west as Milton Keynes; the BBC does however provide BBC Radio Norfolk solely for the county. Brewer Greene King, food producer Cranswick and feed supplier ForFarmers were seeing growth in 2016–2017. A Local Enterprise Partnership was being established by business leaders to help grow jobs across Norfolk and Suffolk. They secured an enterprise zone to help grow businesses in the energy sector, and established the two counties as a centre for growing services and products for the green economy. To help local industry in Norwich, the local council offered a wireless internet service but this was subsequently withdrawn as funding has ceased. The fishery business still continued in 2018, with individuals such as John Lee, a fifth generation crabman, who sells Cromer Crabs to eateries such as M Restaurants and the Blueprint Café. The problem that he has found is attracting young people to this small industry which calls for working many hours per week during the season. Lobster trapping also continued in North Norfolk, around Sheringham and Cromer, for example. Management of the shoreline Norfolk's low-lying land and easily eroded cliffs, many of which are composed of chalk and clay, make it vulnerable to weathering by the sea. The most recent major erosion event occurred during the North Sea flood of 1953. The low-lying section of coast between Kelling and Lowestoft Ness in Suffolk is currently managed by the British Environment Agency to protect the Broads from sea flooding. Management policy for the North Norfolk coastline is described in the "North Norfolk Shoreline Management Plan" published in