Londonderry is consistently at the bottom of the table on measurements like unemployment, incomes and investment. Why has the economic performance of Northern Ireland's second city been so bad? Is it the long legacy of partition and political discrimination? Or has there been failure of leadership in the city? What can be done to reverse the years of economic decline? And could Brexit provide a catalyst for radical new thinking? BBC News NI's business editor, John Campbell, investigates. Reporter: John Campbell Producer: Anna Quigley.