When $COUNTRY role is supplier, the link display is between supplier from $COUNTRY and requesting from other country.
When $COUNTRY role is requesting, the link display is between requesting from $COUNTRY and supplier from other country.
The national links from $COUNTRY to $COUNTRY aren't display.
Only the top 15 country are display the others are group in two category : $OTHER_IN_REGION and $OTHER_NOT_IN_REGION
$COUNTRY : link in the world until $YEAR include