GRAPHIC-Now 21, Britain's AIM is still struggling to grow up

* AIM vs the rest: http://bit.ly/28JoEmv
By Atul Prakash
LONDON, June 20 (Reuters) – With (Other OTC: WWTH – news) a few exceptions, London’s Alternative Investment Market (AIM) is the only segment of the UK stock market that has, on average, lost money over the past two decades.
Britain’s junior stock exchange opened 21 years ago to give investors a way to buy into smaller, unproven companies that promised fast growth, but it has consistently lagged the broader market in