http://www.srh.noaa.gov/sju/hrcnhist.html

As all can see in the link Puerto Rico has been visited many times and also many nearmisses haved occured.I can say that Puerto Rico has been with luck because the position that we are in the caribbean at hurricane alley makes this island a continued target but in many seasons some factors come into play and deviate the systems away however in other occasions those same factors are not there with the luck over and BANG landfalls will happen.Let's see how the factors play this season for threats to be common for the islands or many fish hurricanes are the norm.