I want to know the answer to the following question:
When did many of the largest mobile phone manufacturers sign an EC-sponsored MoU?
All the background I'm provided with is that "In June 2009, many of the world's largest mobile phone manufacturers signed an EC-sponsored Memorandum of Understanding (MoU), agreeing to make most data-enabled mobile phones marketed in the European Union compatible with a common External Power Supply (EPS).". Is that enough to answer the question?