Currency flows and central bank statistics are are two of the most arcane areas of economics. But here's the basic gist: a positive capital flow occurs when money is flowing into a country while a negative flow occurs when money is leaving the country. The former is economically positive; it indicates that foreign investors view the target country as an attractive investment. The latter is bad; it indicates that investors are pulling money out of the country, meaning it's no longer a good investment. Usually accompanying the latter situation are phrases like, "currency crisis," or "balance of payments crisis." There is no good way to spin capital outflow; it is an inherently bad development.
The two charts above show Puerto Rico's capital flows data but in different time frames. The top chart goes back to 1971. For most of that time, Puerto Rico's capital flows fluctuated around 0. That's not great, but not fatal either. That changed at the end of the 1990s when there was a huge capital inflow. But then in 2012 capital flows turn negative. They've been that way for the last six years. There is no good way to spin this data: it is fundamentally very negative. More money is leaving the country than going in.
Here's a historical comparison: the exact same situation happened in Greece:
And why did investors flee Greece? Because it was a fiscal and economic disaster -- just like Puerto Rico, which has been in a recession for the last ten years and where high unemployment is a feature not a bug.
This is not a good jurisdiction for any complex transaction. Period.