Brittany in France is recognized as one of the 6 Celtic Nations: What percentage of the population is Rh negative?

Brittany in France is recognized as one of the 6 Celtic Nations

At the 2010 census, the population of historic Brittany was estimated to be 4,475,295. Of these, 71% lived in the region of Brittany, while 29% lived in the Loire-Atlantique department. In 2012, the largest metropolitan areas were Nantes (897,713 inhabitants), Rennes (690,467 inhabitants), and Brest (314,844 inhabitants). Brittany is the traditional homeland of the Breton people and is recognised by the Celtic League as one of the six Celtic nations, retaining a distinct cultural identity that reflects its history. A nationalist movement seeks greater autonomy within the French Republic.

What does it mean to be Celtic?

The people, jokingly called the “Black Irish”, have dark hair and eyes, wedge-shaped faces and look like Berbers and Basques. Their blood type proves that Berbers and Basques were originally closely related people, as many of them have Rh-negative blood. They are likely the descendants of the first settlers to Ireland and Scotland. This type of people is especially common in Conamara and Donegal of Ireland and on the Outer Hebrides of Scotland.
 
          Today in many publications, the presence of these dark-eyed people is explained as them being castaways of the huge Spanish armada that was defeated in 1588 by a coalition of British and Dutch sailors in the North Sea.  They were wrecked on the islands by storms when the remnants of the fleet tried to sail around Ireland to struggle back home. Many of the sailors had indeed been Basques and several of those that made it safely to land, liked it there and stayed. However, the existence of these dark featured people had already been documented long before the armada was ever thought of. There is little doubt that the Black Irish are the descendants of the oldest population of the British Isles and Ireland.

http://www.faculty.ucr.edu/~legneref/bronze/seapeopl.htm