During the year through June 2015, an amount equivalent to more than 40 percent of Greece's annual economic output fled the country. Bloomberg

Not much private money, though, has come back since then -- reflecting both the effect of capital controls and persistent concerns about whether Greece will remain in the euro area.

Here's a chart showing the three-month cumulative flow of capital between Greece and the rest of the euro area (negative numbers indicate outflows):

Mark Whitehouse, Bloomberg Opinion 3,0 May 2016

Bank Run