In January 2008 the Wapping presses printed The Sun for the last time and London printing was transferred to Waltham Cross in the Borough of Broxbourne in Hertfordshire, where News International had built what is claimed to be the largest printing centre in Europe with 12 presses. The site also produces The Times and Sunday Times, Daily Telegraph and Sunday Telegraph, Wall Street Journal Europe (also now a Murdoch newspaper), London's Evening Standard and local papers. Northern printing had earlier been switched to a new plant at Knowsley on Merseyside and the Scottish Sun to another new plant at Motherwell near Glasgow. The three print centres represent a £600 million investment by NI and allowed all the titles to be produced with every page in full colour from 2008. The Waltham Cross plant is capable of producing one million copies an hour of a 120-page tabloid newspaper.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How much had been invested in the new printing locations?
£600 million