Well, if you find that impressive then you might take a look in the member history of the Boston Crusaders. Over the last few years they’ve had so many foreign members, way more then 7.
Me, I’m from Holland and marched 3 years in Boston in 97 – 99. Those years the foreign members were:
1997: 7 Japan, 4 Holland, 3 England, 1 Schotland, 1 Mexico, 1 Canada, 1 Korea
1998: 13 Japan, 2 Holland, 5 Canada, 1 Schotland
1999: 6 Japan, 5 Holland, 1 Schotland, 3 Canada, 1 England, 1 Thailand
On the 1996 DCI Video/DVD is an interview with all of the foreign members that marched Boston that year. I believe there were around 20 kids from outside the US that year.
If you’re interested in the amount of all the Dutch kids who marched in DCI over the past decades, take a loot at www.dutchindci.com There’s a list with all the names of all the Dutch who marched, where they marched and what instrument/equipment they used.